26 



CURRENT LITERATURE. 



PilsbPy, Henry A. — Trvon's Manual of Conchology, ser. ii., vol. xiv. 

 (pt. 54), pp. 129—192, pis. 22—36. Philadelphia.- Academy of Natural 

 Sciences. 



Continuintj the "Appendix to Bulimoid Snails," the following genera are 

 dealt with, and the undermentioned new species, etc., described : — Plckocliciliis, 

 Guild, Atiris, Spix, Xciiotliaiiiua, Fult., Biilijiuiliis, Leach, with B. stilbc, n. sp. 

 from Brazil, Xcopcfraciis, Marts.. O.vycJioiia, Morch, Drymaeiis, Albers, with 

 D. co^naiiis, n. sp. from Colombia, a speciesclosely related to D. zoo^^eograpliictis, 

 Orb., and D. iiiciiibitiiinis, Crosse. D. snccinea, n. sp. from the Amazon river, 

 resembling in contour D. coliiwlivi, Hid., but differing from that species in 

 sculpture and colour. D. roscatiis var inonfaiuis, nov. and D. saiictaeiuartJiae, 

 n.sp., both from Colombia, the latter, in the spotted pattern of the spire recalls 

 some forms of D. iriiioiiosioiiins, but in the structure of the aperture and colu- 

 mella it is near D. castits. Other genera are Porpliyrobaplic, Shuttl., Oxystyla, 

 Schliiter, Botliriciiibryon, Pils., Placostyliis, Beck, Amphidromits, Alb., and 

 Odoiitostoiiiiis, Beck., with O.ilcincllattts, Ancey, n.sp. from Goyaz, Central Brazil. 

 The Appendix concludes with a list of undetermined Biilhiutlidac. 



In the present part the Ccrioiiidac are commenced. The genus Ccriou, 

 "Bolton," Morch, has by most authors, been associated with the Pupidac, hut Dr. 

 Pilsbry shows that there is little in the anatomy to justify such an association, 

 while the pallial and generative organs show it to belong to a widely different 

 group. 



The genus is diagnosed as follows : — "Lung macroscopically plain except 

 for the pulmonary vein. Kidney oblong, with large cavity, and excreting 

 apparently by a secondary ureter. Genital system having a wide atrium, short 

 penis with terminal retractor, tlic cpipliaJliis entering near or below the iinddle 

 of the penis sac. Vas deferens extremely long. Spermatheca on a long duct 

 which bears a long diverticnlnni.' A vaginal retractor arises from the right 

 ientacniar muscle. Free retractor muscles independent to their posterior ends 

 except the right tentacular and tail retractors, which are shortly united. Jaw 

 smooth. Teeth of the normal type in Holopoda, the ectocones developed. 

 External anatomy as in Holopoda generally ; the labial processes well 

 developed." Type C. iiva, L. 



The species are subject to a remarkable range of individual and local 

 variation, both in size, colour and external markings, and this has led to an 

 undue multiplication of species and sub-species. 



The following sub-genera are recognised : — Cerion, s.str., Strophiops, Dall, 

 Dicicerion, Dall, and Eostropliia, Dall ; the species therein being classified in 

 fifteen groups. 



Biedermann, W. — Untersuchungen iiber Bau und Entstehung der Mollusken- 

 schalen. Jena. Zeit., 1901, Bd. xxxvi., pp. I — 164, Tafn. i — vi. 



The author of this bulky paper starts with the postulate that it is a question 

 of fundamental importance what may be the nature of the process by which, 

 through incalcuable time, vast masses of carbonate of lime have been formed 

 by plants andthe frame work of animals, accumulations such as we meet with in 

 every geological formation, and in the sediments of the sea-iloor. He tiien 

 proceeds to discuss the derivation of the lime by organisms from the sea-water, 

 and announces his intenti(jn of furnishing an opinion, to be based on his own 



