ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 191 



cavity, and sheds its products into the ccelom, whence they reach the 

 right nephridium. He helieves further that there are or were Gastro- 

 pods which had paired gonads related respectively to right and left 

 nephridia. From such forms the Docoglossa originated by the union of 

 the gonads and the degeneration of the left nephridium. In the forms 

 from which the Rhipidoglossa arose the connection between right nephri- 

 dium and ccelom was lost owing to the modification of a part of the latter 

 to constitute a genital duct. Haller also criticises in detail certain of 

 Pelseneer's figures and statements. 



Relations of Land Molluscan Fauna of South America.* — Mr. H. A. 

 Pilsbry has recently discussed this interesting question, but only a sum- 

 mary is published. The evidence of former austral land connecting 

 South America with Australasia (derived from a study of Bulimulidae, 

 Macroogona, &e.) is discussed, and reasons are given for preferring 

 the hypothesis of a former extension of Antarctic laud to that of a South 

 Pacific continent as advocated by Huttou and others. The present 

 Polynesian fauna is not consistent with the supposition that these islands 

 are outgrowths from or remnants of a submerged Pacific continent. It 

 is maintained that the neotropical region of Wallace is composite, the 

 Antillean and southern Mexican area representing a tract independent 

 from North and South America in Mesozoic and perhaps earlier times, 

 on which the faunal problems had been independently worked out. 



Structure of Neritina.f — Prof. J. Lenssen describes, in this instal- 

 lment of a proposed monograph on Neritina fluviatilis, the alimentary and 

 reproductive systems. Considerable space is given to the buccopharyn- 

 geal apparatus, including the cartilage and muscles of the radula. The 

 •oesophagus shows two remarkable ciliated grooves which may perhaps 

 represent the oesophageal salivary glands of other Prosobranchs. On 

 the internal surface of the complex stomach wall there is an interesting 

 ridge of doubtful function, and the minute structure of the whole region 

 is very remarkable. 



Claparede's description of the female apparatus is corrected. What 

 is most remarkable, perhaps, is the occurrence of two apertures — one for 

 impregnation and one for copulation. This arrangement is due to a 

 birurcation of the oviducal canal. Special attention is paid to the glands 

 of the uterus, and to their process of cellular excretion. To the male 

 apparatus there is but one opening ; it has an interesting glandular 

 annex, ciliated internally, and with parietal cells analogous to those of 

 the uterus. 



5. Lamellibranchiata- 



Affinities of Solemyidae.J — Dr. Walter Stempell has investigated the 

 anatomy of Solemya togata Poli, as a supplement to his work on the 

 Nuculidas, with the special object of determining the value of Pelseneer's 

 order Protobranchiata, constituted by these two families. The anatomy 

 ■of the form is described in detail, and is illustrated by some admirable 

 £gures ; but we can here only notice the bearing of the results on the 

 general question. 



The author accepts the order Protobranchiata with the following 



* Proc. Acad. Sci. Philadelphia, 1899, p. 226. 

 t La Cellule, xvi. (1S99) pp. 179-232 (4 pis.). 

 X Zool. Jahrb. (Abt. Anat.), xiii. (1S99) pp. 89-170 (3 plsA 



