摘要:

SUMMARY1The internal structure and function of the stomach is described for representatives of seventeen families of Eulamellibranchia.2Detailed comparisons are made among these and comparable data previously obtained from four families in the Filibranchia and Pseudolamellibranchia, and it is concluded that there are no grounds for sub‐dividing these twenty‐one families into two or more groups. In all cases the stomach is of Type IV.3A new definition for Stomach Type IV is provided.4It is concluded that on the basis of the internal structure of the stomach these twenty‐one families appear to comprise a natural and monophyletic assem

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00700.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00701.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYA new species and genus,Pumilus antiquatus, of kraussinid brachiopod from shallow water, Lyttelton, New Zealand, is described and figured. It is characterized by the possession of a schizolophous lophophore in the adult, supported by both divergent lamellae and spicules: the shell is smooth, less than 5 mm. long and strongly sulcate. The gonad is hermaphrodite.Notes are given on the ciliary feeding mechanism.The affinities ofP. antiquatusare briefly discussed: it is placed in the Kraussinidae.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00702.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYSixteen recently metamorphosed and forty‐seven mature frogs were captured and the stomach contents examined. In view of the more limited choice of available prey imposed upon the former, due to the smaller jaw span, it was decided to tabulate the contents separately.Aposematic prey formed a substantial proportion of the diet.Large numbers of flowers were recovered from several stomachs.Specific choice of prey varied with the individual, and it was concluded thatR. esculentaas a species is not selective.In the natural habitatR. esculentadoes not by choice leave the water to feed unless there are insufficient aquatic prey.It was found that mature adult frogs showed cannibalistic tendencies and this, coupled with a thermotactic response, influenced their distribution within the habita

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00703.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYA new species of the genusEukrohnia, E. bathyantarctica, is described; it is a deep living form, so far only found in the Southern Ocean. It resembles bothE. fowleriandE. hamatain many features. Evidence is given which suggests that in this species, and also inE. fowlerithe seminal vesicles function as spermatophores and are attached intact to the external opening of the oviduct by a fine tube which is probably the vas deferens.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00704.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARY1A study has been made of the maxillary nerve in eighty‐three specimens of nineteen species of placental mammals. The series included representatives of six mammalian orders.2In this material, the maxillary trunk first gives off the zygomatic nerve and then passes forwards on the orbital floor. It gives origin to the posterior and anterior superior dental nerves, and splits at a variable point into nasal and labial divisions. The nasal division supplies the surface of the snout, the rhinarium and the vestibule of the nose, frequently giving twigs to the uppermost members of the group of mysticial vibrissae. The labial division is distributed to the remainder of the mysticial vibrissae, and to the skin of the cheek and upper lip.3If the rhinarium or the uppermost mysticial vibrissae are prominent, the nasal division is correspondingly big.4If the lower members of the group of mysticial vibrissae are well developed, it is the labial division that is relatively enlarged.5The relative sizes of the facial branches of the infraorbital nerve are also affected by the development of specialized facial features—e.g. in the pig the vast majority of nerve fibres are distributed to the disc‐like ending of the snout.6Certain structures presumably derived from the frontonasal process receive their nerve supply from the nasal division, while those derived from the maxillary processes are normally supplied by fibres from the labial division. In the ungulates, however, the nerve supply to the mobile upper lip is derived from branches of the nasal div

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00705.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00706.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

摘要:

SUMMARYExamples are given to show how in the Bivalvia, (a) changes in the form of the mantle/shell may affect the position of the adductor muscles, and (b) secondary extension of the primary ligament may limit the extent of pallial attachment in the anterior and posterior embayments of the mantle.Secondary extension of the ligament may take place by periostracum or by fusion layer but it is probable that only fusion layer is of functional significance. Where the outer surfaces of the outer folds of the mantle margins anterior and posterior to the mantle isthmus are fused, as in the formation of fusion layer, there is an accompanying loss of pallial attachment and in most, if not all bivalves, the pallial line extends to the anterior and posterior ends of the functional ligament whether this consists of primary ligament only, as inMytilus edulis, or of primary ligament secondarily extended by fusion layer, as inAnodonta cygnea.The extent of the pallial muscles in the anterior and posterior embayments is therefore of use in distinguishing between (a) fusion of theinnersurfaces of the outer folds (i.e. when the two valves are joined byperiostracum) and (b) fusion of theoutersurfaces of the outer folds (i.e. when the two valves are joined byfusion layer).Elongation of the mantle/shell on either side of the demarcation line results in a corresponding extension of the region of cross fusion of the pallial muscles in the anterior and posterior embayments. For functional reasons the adductor muscles develop new the anterior and posterior margins of the shell and as a result, in many bivalves pallial attachment extends beyond the adductors to the anterior and posterior ends of the functional ligament. This feature of pallial attachment in the Bivalvia appears to have been overlooked.

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00707.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY

ISSN:0370-2774    

DOI:10.1111/j.1096-3642.1958.tb00699.x

出版商:Blackwell Publishing Ltd    

年代:1958

数据来源: WILEY