1892.] NATURAL SCIENCES OF PHILADELPHIA. 395 



The only species known is A. grateloupi Grsells (grccllsiana Pfr.), 

 of the Island of Majorca. Probably H. quedeiifehlti Mts. belongs 

 here, also, as Kobelt suggests. 



Genus COCHLOSTYLA (Fer.) Semper. 



Genitalia: 9 system having a globular mucous gland united with 

 the dart-sack ; $ system usually without a flagellum. Jaw strongly 

 ribbed, rarely smooth. Brilliantly colored shells of arboreal 

 habits, confined with a few exceptions, to the Philippine Islands." 



Genus POLYMITA (Beck) Binney. 



Genitalia as in Hemitroclmis. Jaw low, wide, arched, delicately 

 striated, without ribs or median projection. 



Teeth with a long quadrangular basal plate with gouge-shaped 

 expanded cusp. 



Shell globose, brilliantly colored, with simple lip. 



This genus holds much the same relation to Hemitrochus that 

 Allorinathus holds to Helix. The extremely peculiar dentition, first 

 made known by Binney, is very different from that of ordinary 

 Helicoids, but is approached by a number of other fruit-eating 

 arboreal snails. The species are all Cuban. 



Genus HEMITROCHUS (Swainson) Pilsbry. 

 Man. of Conch. (2), V. p. 5. Proc. A. N. S. Phila. 1892, p. 129, pi. 6, tigs. F, G. 



Genitalia : ? system having a dart-sack and accessory mucous 

 glands ; duct of the spermatheca long, simple. $ system having a 

 slender penis at the apex of which the vas-deferens and a long 

 flagellum are inserted ; retractor penis lacking. 



Jaw highly arched, smooth except for some faint vertical striae 

 in the middle. 



Dentition of the normal Helix type. 



This group includes the sections Hemitrochus, s. str., Plagiop- 

 tycha, Dialeuca, Coryda, and perhaps Jeanneretia. Possibly the 

 continental section Oxychona belongs here. The species are all 

 West Indian, inhabiting from Jamaica and Haiti northward to the 



i*Under Cochlostyla are included the sections enumerated by Semper (Land 

 Moll. Phil. Arch.), several additional sections propc-ed by myself (Manual of 

 Conch. (2), vii), and the curious Helix cepoideso^ Lea, formerly classed in Siylo- 

 donta, but referred to Cochlostyla by Dr. v. MoellendorfT, under the sectional 

 name Ptychosiylus. This name beinjr preoccupied by Sandberger for a tertiary 

 genus of Melatiiida:. a substitute must be chosen ; we propose, therefore, to des- 

 ignate the group Hypoptychus; H. cepoides Lea being the type, and thus far the 

 only known species. 



