LEPTAXIS. 291 



below, and bears in the middle a diverticulum 27 mill, long, not 

 bound to the uterus. Dart-sack large (6 mill, long), containing a 

 a four-bladed dart with expanded funnel-shaped crown ; above the 

 sack are inserted two mucus-glands, each split into two large, club- 

 shaped fingers. Penis 16 mill, long, cylindrical, the retractor mus- 

 cle terminal; flagellum 37 mill, long (pi. 36, fig. 1, A. graellsiana 

 Pfr.). 



This genus is founded upon a single species inhabiting the Bale- 

 aric Islands. The shell furnishes no characters of more than specific 

 value, separating it from such species of Otala as beaumieri, 

 etc. ; and it is by no means impossible that this and some other 

 species, such as H. quedevfeldti Mts., may prove to belong to Allog- 

 nathus. Notwithstanding this similarity of shell, we find in the 

 anatomy profound differences from all other Pentatseniate Helices. 

 The jaw is smooth, as in Leucochroa; the teeth are very aberrant 

 in the narrow basal-plates which curve over into a blunt, strap-like 

 cusp, entirely lacking side cusps, and they are alike over the whole 

 radula. The genital system presents a resemblance to Cawpylcea in 

 the two-fingered mucous glands, but is otherwise more like the 

 Pentatseniate groups. We are disposed to consider Allognathus a 

 special modification of the Helix stock, comparable to the Poly- 

 mita off-shoot from Hemitrochus. 



A. graellsiana Pfr., iv, 150. 



grateloupi Graells not Pfr. tessellata Fer., not Miihlf. 



Genus LEPTAXIS Lowe, 1852. 



Leptaxis LOWE, Ann. Mag. N. H. (2), ix, p. 164, Feb., 1852 ; P. 

 Z. S. 1854, p. 164, type H. erabescens Lwe. Katostoma LWE., P. S. 

 S. 1854, p. 166, type H. phlebophora Lwe. MacAilaria sp. LWE., i. 

 c.j p. 166. Cryptaxis LWE., t. c, p. 168, type H. undata Lwe. 

 Campylcea sp. LOWE. Pseudocampylcea PFR., Mai. Bl. 1877, p. 8- 

 Nomencl. Hel. Viv. 1878, p. 162, types lowei and portosandana. 

 Lampadia Alb. MSS., LWE., P. Z. S. 1854, p. 197, type H. webbiana 

 Lwe. (Not " Lampadie/' Montf., French vernacular name for Lam- 

 pas Montf.). Mitra ALB., Die Hel. 1850, p. 115, type H. webbi- 

 ana ; (not Mitra Lamarck.) 



Shell of moderate or large size, globose, globose-depressed or lens- 

 shaped and keeled, imperforate (rarely umbilicate), the surface 

 striate, plicate, granulated or malleated ; rather thin ; uniform 



