ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02286.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

Summary1A detailed study has been made of the morphology and systematic position of two brackish‐water Actiniaria from Madras.2The anemones are sphincterless Athenaria having acontia, and belong to the family Halcampactiidæ.3In structural features the two anemones differ from other known Halcampactids, and this necessitates the creation of two new genera, for which the namesPhytocosteopsisandStephensonactisare proposed.4Complete generic and specific definitions ofPhytocosteopsis ramunniiandStephensonactis ornataare given.5The oral disc is very much contracted in both the Actinians, the throat being open and the distal part of the actinopharynx always remaining in an everted condition.6There are twelve prominent, lobed, throat ridges inS. ornata, while such separate ridges are absent inP. ramunnii.7The tentacular arrangement inP. ramunniiexhibits a curious atypical condition, caused by the interchange of the apparent positions of the tentacles of the last two cycles and an undue development of those of the fourth order and their corresponding endoccels.8The acontia, which are numerous inP. ramunnii, show interesting features of distribution, correlated with the probable order of succession of the macrocnemes. They also show variations in their positions of origin from the mesentery.9The peculiarities of the tentacles and acontia inP. ramunniiare features not previously observed in any Actiniaria.10S. ornatahas the tentacles and acontia arranged in the normal way, as in the typical Actiniaria.11The general features of anatomy and histology ofS. ornataandP. ramunniiare similar.12An account of the bionomics of the two anemones is given, and an attempt is made to explain some of the morphological and histological peculiarities, in correlation with their habits.13The colour‐patterns ofS. ornataare described.14PhytocosteopsisandStephensonactisbridge the gap betweenPhytoccetesandPelocostes.Since these four genera exhibit several common characters different from other Halcampactids, a suggestion is made to group them separately in one fa

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02287.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02288.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

Summary1An analysis by the method of Huxley of approximately 4000 measurements made on about 1800 individuals ofCancer magisterfrom the Pacific coast of North America is here presented.2Slight heterogony has been found in the growth of the majority of its parts. In all aspects of relative growth it is extremely conservative.3Changes in form indicate that sexual maturity in the female occurs at a carapace width of about 10 cm. This is confirmed by the size of ovigerous females and by observations of the development of the ovary.4The sudden change in the length‐width proportions indicates that sexual maturity is usually attained by a single moult.5The size at which male crabs become mature could not be inferred with certainty from the present data.6After sexual maturity has been attained the legs of male crabs grow more rapidly than the body and the legs of females continue to grow less rapidly than the body. As a consequence the legs of mature males are longer than those of mature females of corresponding carapace width.7A change in the ratio of length to width of the sixth abdominal segment of females has been noted at a carapace width of 7 cm. No other change is known to occur at this size. It is possible that this is a precocious change associated with the approaching sexual maturity.8Crabs from south‐eastern Alaska, both male and female, were found to be a little shorter in proportion to their width than the corresponding Boundary Bay crabs.9It has been pointed out that most organisms display some heterogony and that bizarre forms must exhibit it to a greater degree than more conservative forms.10It has further been pointed out that a strong negative correlation seems to exist between the degree of heterogony and the maximum size of a species. Unfortunately no data justifying speculation upon the causal relationships are available.11Cancer magisterin all aspects of relative growth displays great conservatism; no high values forkwere found for this large and abundant spec

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02289.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02290.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

SummaryVorticella campanulaand F.chlorostigmaperiodically form swarms of free‐swimming individuals. All the members of a sessile group leave their stalks at the same time. The resulting swarm is held together by mucus which the free‐swimming animals secrete. After a time the swarmers settle again in groups, and grow new stalks. Swarming is apparently not connected with asexual reproduction or with conjugation. Its cause is unkn

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02291.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02292.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

摘要:

Summary1This paper describes the subcutaneous venous system ofScyliorhinus (Scyllium) caniculus, the Common Dogfish. Previously no complete account of this system appears to have been given for any Selachian.2Practically the whole surface of the animal is covered by a dense network of veins.3In the trunk and tail these superficial networks drain into dorsal, ventral, and lateral longitudinal vessels.4In the pharyngeal region the superficial networks are connected directly to the underlying venous sinuses.5The veins of the fins are connected to the cutaneous venous system.6Immediately below the skin lining the mouth and pharynx are the bucco‐pharyngeal networks of veins. They cover both the dorsal and ventral walls of these cavities, and drain into the principal sinuses of the anterior part of the fish. Posteriorly they are continuous with a fine plexus of vessels surrounding the esophagus. Only the dorsal bucco‐pharyngeal vessels have been previously descri

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02293.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1936.tb02294.x

出版商:Blackwell Publishing Ltd    

年代:1936

数据来源: WILEY