摘要:

The taxonomy and morphology of Aktedrilus Knöllner, 1935 and Bacescuella Hrabe' 1973 (subfamily Phallodrilinae), both common genera of the marine, littoral meiofauna, were studied on the basis of material from various geographical areas. A. monospermathecus Knöllner, 1935 is redescribed from France and Scotland. A. magnus sp.n., A. hrevis sp.n., A. curvipenis sp.n. and A. floridensis sp.n. are described from Italy, Brazil, France and Florida, respectively. Two very closely related forms are described from the Pacific: A. locyi sp.n. (California) and A. parviprostatus sp.n. (Great Barrier Reef). B. mediterranea sp.n. is described from Italy, and new European records are given forB. arclica Erséus, 1978 andfi. parvithecata Erséus, 1978. Both genera are characterized by having two pairs of prostate glands, well developed penes, and unpaired, mid‐dorsal spermatheca (if present). The species of Bacescuella transfer their sperm by means of external spermatophores, structures that are not developed in Aktedrilus. The eight species of Aktedrilus are largely distinguished by means of the morphology of the spermatheca, penes and prostates. The four species of Bacescuella differ principally from each other in the length of the vasa deferentia, and in the morphology of the prostates and copulatory organs. Most Bacescuella species lack sperma

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00656.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The family Echiniscoididae, comprisingAnisonychesPollock, 1975 andEchiniscoidesis erected. Members of the latter genus were found in barnacles collected from the coasts of the USA, Greenland, Norway, Sweden, Denmark, France and Spain. From this material and from available museum specimens it can be concluded that two species ofEchiniscoidesexist.E. hoepnerisp.n. is parasitic inBalanus balanoidesin W Greenland.E. sigismundi(M. Schultze, 1865) is a complex of small species mainly distinguished by its co‐variation of cutic‐ular and claw features.E. sigismundi groenlandicussubsp.n. appeared from the coasts of the USA, Greenland and Norway. For E.sigismundis.str. we were forced to establish a neotype typical of the findings from S Norway to N France, thus including the traditional finding places of this species. Less widely distributed are perhapsE. s. galliensissubsp.n. (N France), E. s.hispaniensissubsp.n. (N Spain, the Atlantic coast) andE. s. mediterranicussubsp.n. (the Mediterranean coast of N Spain).E. s. polynesiensisRenaud‐Mornant, 1976 is recorded from Melbourne (Australia) and against the background of the other subspecies an amended diagnosis is presented. Key characters are provided and besides an analysis of the variation of taxonomic characters, a brief account of the biology and ecology of the members ofEchiniscoidesis

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00657.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The ultrastructure of potential photoreceptors in larvae ofTricellaria occidentalisand four speciesof Bugulais described and compared with previously reported photoreceptors in larvae ofBugula neritinaandScrupocellaria bertholetti.A single sensory cell forms the functional unit of each photoreceptor. This cell is distinguished by a concentration of pigment vesicles in its apical part, a direct connection with the nervous system, and a large number of cilia that form the photoreceptoral organelle. These cilia have axonemes morphologically identical to those of motile cilia. The membranes of sensory cilia are unbeaded and qualitatively less osmophilic than those of the motile cilia of adjacent accessory and coronal cells. Three photoreceptor types are designated based on topological complexity: Type I, in which the sensory cell is flush with adjacent coronal cells and the photoreceptoral organelle is unprotected; Type II, in which the apical surface of the sensory cell is invaginated, forming a lumen containing the photoreceptoral organelle; and Type III, in which the sensory cell is at the base of an epidermal invagination and the photoreceptoral organelle is protected in a lumen formed by the sensory cell and accessory cells. There is a greater range of morphological variation among photoreceptors in larvaeof Bugulaspp. than between those of two species of the related generaScrupocellariaandTricellaria.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00658.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Five species of cyclostomatous Bryozoa are reported in an assemblage from the Red Sea at Eilat, Israel.Tuhulipora samuelsonisp.n. is described. The fauna is closely related to known Indo‐Pacific fauna

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00659.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

InPlourdosteus. Pholidosteusand other brachythoracids, the gnathalia exhibit a limited number of dental fields with much the same distribution pattern. Each of these either carries semidentine teeth or marks the location of a column of semidentine (or, in cases, other dental hard tissue) which phyletically represents the product of fusion of originally independent teeth. The basal portion of the superognathalia and of the biting division of the inferognathal were regions of active growth where formation of new hard tissue went onpari passuwith the abrasion on the biting areas of the plates. The inferognathal formed during ontogeny by the fusion of two separate elements, a dental component on which all the dental fields of the plate were situated, and an axial component which was devoid of such fields. InHolonema, the narrow ridges on the lingual side of the gnathal plate of the lower jaw consist in part of semidentine; even these formed phyletically by the fusion of teeth. Dermal jaw‐elements with quite the same developmental and structural features as those of brachythoracid or holonematid arthrodires are unknown in other fishes, including elasmobranch

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00660.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

Coelogynopora sieinooeckisp.n. andC. hamulissp.n., are described from sublittoral sediments of the North Sea.C. hamulisalso occurs in an eulittoral lower beach slope.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00661.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

The number of abdominal segments in Tipulomorpha and Bibionomorpha larvae and aduts is discussed. For Nematocera, the most primitive number of abdominal segments in both male and female larvae is nine. Reduction of the IX abdominal segment and its subsequent fusion with the VIII segment occurs in different phyletic lines in Nematocera and might have evolved several times. InTrichoceraspp. nine abdominal segments are present. In the genital segments the main interrelationships in the position of the anus and some main innervation areas, especially the ventral lobes, and the derivatives of the genital primordia were followed during postembryonic reorganization by studying variously stained serial sections from all developmental stages from the first larval instar to the adult stage. Homologies between male and female derivatives of the IX segment genital primordium were established for Trichoceridae. The trichoceroid male claspers and female ovipositor were found to be of sternal origin and highly specialized structures. They appear to be unique features of the Tipulomorpha. Postembryonic development inLimonia nubeculosaMeigen, 1804 andSylvicola cinctu(Fab‐ricius, 1787) was studied in the same way. InLimoniamales the trichoceroid functional system for grasping is present. In Anisopodidae (Sylvicola), another functional system for grasping has been evolved by the male, which only includes primordial derivatives. In the adults, fusion of the VIII and IX segments prevents development of outer clasping organs or special structures for egg guidanc

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00662.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

All species that have been described of the genera mentioned in the title are listed and their systematic position given. The species ofStilifer(with 11 species, includingS. inflatussp.n. and 5.concavussp.n.) are parasites of starfishes.Scalenostoma(3 species) are parasites of stone corals.Thyca(with 8 species) is removed from Capulidae, and included in Eulimidae.T. hawaiiensissp.n. is described. The species ofThycaare parasites of starfishes. The species ofMucronalia(includingM. trilineatasp.n.) are probably parasites of ophiuroidsand Echineulima(with 4–6 species, includingE. ponderisp.n.) are parasites of echinoids. All species are figured, their characteristics are given and their host species and distributions are listed. Keys are given to the species of each genus, exceptMucronalia.The generaStilimellaLaseron andHyperliaPilsbry are synonymized withScalenostomaand the generaKiramodulusKuroda,GranulithycaHabe andBessomiaBerry are considered subgeneraof Thyc

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00663.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

In the Bryozoa in general the colony is attached by means of the primary zooid, the ancestrula, which is permanently cemented to the substratum. The attachment is brought about, in the marine bryozoans, by the larva everting its interior sac into a basal adhesive disc secreting a thin layer of hardening mucus. InScrupocellaria reptansno adhesive disc was found. The metamorphosing larva is fixed to the substratum by a column of loose, sticky secretion. This primary fixation is ephemeral and replaced by a secondary, permanent fixation by one pair of rootlets. Thus, the ancestrula body proper and the colony arising from it become permanently free from the substratum but anchored to it by rootlets, the primary pair and series of secondary rootlets. This unique and certainly secondarily evolved type of attachment is apparently realized in the Scrupocellariidae in general, to a more or less perfect degree. It appears as one of several possible models to meet efficiently with environmental disturbances.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00664.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY

摘要:

An account is given of the structure and growth of certain ptyctodontid tooth plates, especially thoseof Ctenurella gladbachensis, based on study by light microscopy and the SEM. These tooth plates consist of a framework of acellular bone tissue and an interior hard tissue referred to as pleromin. It is concluded that the pleromin is neither dentine nor enameloid in the strict sense, being distinguishable from the former by its hypermineralization and lack of lamellation, and from the latter by its continuous growth, its inclusion of bony trabeculae, sometimes even vascular canals, during this growth, and its process of mineralization taking place without any participation of epidermis cells or secretion products of such cells. It is also different from the semidentine or other dental hard tissue in the dermal skeleton of arthrodires such as e.g. the brachythoracids. Because of their structural peculiarities, ptyctodontid tooth plates can hardly have been derived phyletically from arthrodiran gnathalia of the kind met with in e.g. arctolepids, brachythoracids or holonematids.

ISSN:0300-3256    

DOI:10.1111/j.1463-6409.1980.tb00665.x

出版商:Blackwell Publishing Ltd    

年代:1980

数据来源: WILEY