1892.] NATURAL SCIENCE.S OF PHILADELPHIA. 129 



one, are strongly odontognathous, another proof that this character 

 is worthless for dividing genera or sections among the Helices. 



Caracolus (Lucerna) acutus (PI. VI, tig. A.) has a short flagellum, 

 but much longer than that of C. rostratus. The duct of the sperraa- 

 theca is long. The jaw (PI. VI, fig. B) has strong, unequal ribs. 



Hemitrochus (Placfiopfycha) salvatoris has the same type of jaw 

 which Binney has described and figured for H. varians the typical 

 species of Hemitrochus. In the present species, which belongs to the 

 section Plagioptijcha, the jaw (PI. VI, fig. G) is highly arched, has a 

 feeble median projection, and a group of faint vertical strise in the 

 middle. The genital system (PI. VI, fig. F) is complicated by the 

 presence of a large dart sac, several unequal accessory glands, (a. 

 gl.) corresponding to the " digitate glands " of the restricted genus 

 Helix {H pomatia, etc.). The penis (p.) is slender and tAvisted. 

 It bears a long flagellum of the " whip-lash " type. I found no 

 retractor muscle attached to the jienis, but I suppo.se that there 

 is one. 



I have not commented on or figured the teeth of these forms, as 

 Binney has already investigated those of numerous allied species. 



These few species serve to show the marked difference existing 

 between the genital systems of the two main genera of West 

 Indian Helices: — Caracolus and Hemitrochus. 



Explajiation of Plate VI. 



A. Genitalia of Caracolus (Liicerna) acutus Lam. drawn from a 



specimen collected by Wm. Fox, in Jamaica (Mus. No. of shell, 

 61,632.) 



B. Jaw of the same. 



C. Genitalia of Caracolus rostratus Pfr., (Cuba), obtained from a 



bunch of bananas. 



D. Same specimen, from the opposite side. 



E. Jaw of the same specimen. 



F. Genitalia, of Hemitrochiis (^Plagioptycha) salvatoris Pfr. Drawn 



from a specimen furnished by Wm. H. Dall. (Mus. No. of 

 shell, 62,941). Wattlings Id., Bahamas. 



G. Jaw of the same individual. 



(P. penis, /f. flagellum, p. r., retractor penis, r. s. spermatheca, a. gl. 

 accessory glands. 



February 23. 

 The President, General Isaac J. Wistar, in the chair. 

 Thirty-two persons present. 



The death of Henry Walter Bates, a correspondent, February 17, 

 was announced. 



The following were elected members : — 



