摘要:

Seven specimens, which have been collected on mesolittoral formations, can be assigned with some assurance toOnchidella celtica(Cuvier, 1817). Anatomical studies will provide further evidence. The photographs show the living animal and the radula.

ISSN:0373-4137    

DOI:10.1080/11250007809440129

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The author has carried out a qualitative and quantitative research about freshwater molluscs on the east coast of Garda Lake. Much attention has been paid to the vertical range ofDreissena polymorpha(Pallas). This mollusc has been found at a depth of 50 meters and colonies reaching a population density of 20 000 specimens per square meter have been found.

ISSN:0373-4137    

DOI:10.1080/11250007809440130

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The atypical spermatozoon of Scalidae (Gastropoda, Prosobranchia) has been studied under the optic and electron microscope in the male genital tract.

ISSN:0373-4137    

DOI:10.1080/11250007809440131

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Some doubtful taxonomic structure of three mediterranean species of the GenusChiton(C.olivaceus, C. corallimtsandC. phaseolinus) are comparatively examined by means of scanning electron microscope. Radula and aesthetes show rather uniform morphology and so are useless as diagnostic features. Only the upper scales of the girdle appear different enough to be considered an useful character in taxonomic studies.

ISSN:0373-4137    

DOI:10.1080/11250007809440132

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The wall of the gonad ofGoniodiscus rotundatus, according to ultrastructural observations, may be subdivided in functional unities similar to the acina ofLimnaea stagnalis. Every U shaped functional unity has cuboidal cells (cells 1) at the proximal ends, and flattened cells (cells 2) at the bottom. The transitional zone between the two cells types is just the same as the “germinal epithelial ring”. Ultrastructural study confirms the subdivision of the gonad in a series of periferically located female compartments and a central male one, which are separated by “somatic” cells.

ISSN:0373-4137    

DOI:10.1080/11250007809440133

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Having localized a sizeable population ofGibbula leucophaea(Phil., 1844) along the coasts of Tuscany south of Talamone, the Author records the data from this and other findings, on the hypothesis that sand-mud sea bottoms, with vegetation ofZostera, represent the preferred habitat of the species. Following the comparative examination of some of the morphological characteristics of the shell and radula ofG. leucophaeaand of the similarG. philberti(Récl.), the specific identity ofG. leucophaeais ascertained.

ISSN:0373-4137    

DOI:10.1080/11250007809440134

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

The Author, taking as his starting-point numerous findings of specimens belonging to the genusVenerupiswith particular morphological characteristics, has come across clear written references to the existence in the Mediterranean of a fifth species in addition to the four best known (V. decussata, V. geographica, V. aurea, V. rbomboides). They allude toVenerupis lucens(Loc), which, on the basis of observations and comparisons carried out, has been found to be a valid species. Furthermore, data are provided as to the preferred habitat of the species and its geographical distribution.

ISSN:0373-4137    

DOI:10.1080/11250007809440135

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

Some samples collected by dredging on the outer shelf and on the slope off the Apulian coast, were studied for their malacological content. On a shallow water assemblage withOstreagr.edulisa sequence was recognized beginning with a fossil community withPseudamussium septemradiatumof Würmain age followed by a Postwürmian community withPuncturella noachina - Pilidium fulvum - Homalopoma peloritanum; both the last assemblages are interpreted as Residual Fossil Communities,sensuFageström (1964). Only in recent time the increased depth, temperature and perhaps salinity allowed the settling of the modern biocenoses recognized as Biocoenose des Fonds Detritiques Côtiers and Biocoenose des Fonds Detritiques du Large,sensuPérès and Picard (1964).

ISSN:0373-4137    

DOI:10.1080/11250007809440136

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor

摘要:

This is a scanned image of the original Editorial Board page(s) for this issue

ISSN:0373-4137    

DOI:10.1080/11250007809440128

出版商:Taylor & Francis Group    

年代:1978

数据来源: Taylor