Occasional Papers of the Museum of Zoology 47 



points of light. For the same reason, the number of cusps on 

 the outermost marginals, and perhaps the exact number of the 

 teeth themselves, is indeterminable without resort to ultra- 

 microscopic methods. On the first radula, in which the basal 

 membrane disintegrated while under examination, so that the 

 teeth spread out quite evenly in all directions, I thought I 

 could count 15 marginals, in the other but 13. All of the inner 

 teeth are quite of the same shape as those of G. gnndlachi. 

 The jaw is also very similar in the two species, but that of 

 G. stcrkii is even more nearly semicircular in outline. 



Guppya gnndlachi, subspecies orosciana von Martens (1892). 

 — Two specimens, found in humus among rocks near Laguna 

 de Catemaco. This mountain subspecies agrees with typical 

 gnndlachi in the prominence of the spiral lines and in general 

 shape, but dififers in the marked carination of the last whorl. 

 However, specimens with a distinct angulation were also found 

 in the lowlands (H, I, a) among those with more rounded 

 whorls. 



Guppya (Habroconus) troclmlina (Mo.) (1851). 

 HcUx sclcnkai Pfeififer (1866). 



Thirty-four specimens; adults on leaves of palms and trees, 

 in lowland forests (H, I, b) and in savannah forests (H, III, 

 b) ; juvenile specimens from elephant-ears along Arroyo 

 Hueyapam (H, II, a) ; and one dead specimen from humus 

 amongst rocks near Laguna de Catemaco. An arboreal species 

 found with Helicina, Drymacus, and Oxystyla. 



The jaw (fig. 5) and radula of this form were also examined 

 from two dried animals. The jaw is very similar to that of 

 the general group. The formula of the radula (fig. 4) is: 

 I II 18 19 8-9 0-2 



C — ;L — ;M- + — + + ; 



33234 I 



or (48, 45)-ii-i-ii-(48, 45). The proximal portion of the 



