ZOOLOGY AND BOTANY, MIOBOSCOPY, ETC. 195 



ing. The Pteropods are now regarded as Gastropods; in this Fol, 

 Spengel, and Grobben, who refer them to the Euthyneura, as well as 

 Boas and Pelseneer, who rank them with Opisthobranchiata, agree with 

 the older views of Souleyet and de Blainville, who placed the Pteropods 

 beside Bulla, Gastropteron, and Aplysia. They are Gastropods modified 

 for pelagic life, and on such an understanding their peculiarities are to be 

 interpreted. The protopodium of Pteropods is the sole of the Gastropod 

 foot, not only morphologically, but also in function, as Souleyet pointed 

 out for Pneumodermon. The epipodia are paired derivatives of the 

 protopodium, as Grobben has previously mentioned in regard to the 

 pterygopodium of Heteropods. In a certain sense they may be termed 

 new structures. 



y. Gastropoda. 



Generative Apparatus of Lymnseus.*— Dr. J. Klotz supports 

 Brock and Eouzaud in the statement that the generative apparatus of 

 the Pulmonata begins to be developed before the escape of the embryo. 

 The penis is developed independently at the hinder margin of the 

 tentacle, and is an ectodermal invagination which is hollow, and not 

 solid, as stated by Eisig. There is no " migration ontogenique " of the 

 penis, as supposed by Eouzaud, in Lymnaeus ; further investigations 

 must show whether, in other Basommatophora, the penis is to be regarded 

 as a diverticulum of the female efferent duct. Both uterus and prostate 

 are at first hollow, and, apparently, mesodermal in origin. The 

 cylindrical portion of the vas deferens forms a secondary connection 

 between the penis and the uterine prostatic portions ; there is no rudi- 

 mentary male duct in the sense of Brock. The hermaphrodite gland has 

 an independent mesodermal origin, as Eisig and Brock have correctly 

 stated ; Eouzaud was wrong in affirming it to be ectodermal. The 

 general statement of previous writers that the uterus and prostate are 

 separated only by the ingrowth of a fold into the common duct is 

 correct ; a further dorsal fold in the prostate is the cause of the forma- 

 tion of the pyriform body. The receptaculum seminis is formed by a 

 further fission of the uterus. By a fold similar to that of the prostate 

 the small tube at the proximal part of the rudiment of the penis is 

 formed. The albumen-gland is an evagination of the oviduct. The 

 folds in the uterus appear very early, and the glandular cells in it are, 

 in the Basommatophora, only epithelial cells, but those of the prostate 

 are not so, and they are difibrently arranged to those in the uterus. The 

 glandular cells of the albumen-gland are likewise epithelial, but they 

 do not, as Semper supposed, lie freely in the follicles, for they are 

 connected with an efferent duct. Folds similar to those of the uterus 

 are found in the receptaculum, but are not so numerous. The small 

 tube is separated peripherally from the copulatory organ, and can be 

 completely invaginated. In a large number of points the author agrees 

 with Brock and Eouzaud, and in an almost larger number he contra- 

 dicts Eisig. 



Anatomy of Aplysia.!— M. E- Saint-Loup has some anatomical 

 notes on a form of Aplysia fasciata, which is smaller, more active, and 

 more highly coloured than ordinary examples. He finds that its 



* Jenaische Zeitschr. f. Naturwiss., xxiii. (1888) pp. 1-40 (2 pis.). 

 t Comptea Eendus, evil. (1888) pp. 1010-12, 



