Occasional Papers of the Museum of Zoology 9 



BULIMULID.^ 

 Bulinnilus coriaccus (Pfeiffer) (1857). Two quite typical 

 specimens, except for their grayish color, on the ground in a 

 banana plantation at the edge of the jungle, near Lake Cate- 

 maco. The larger measures : 



Altitude Greatest diameter Height aperture Diameter aperture 



19.8 mm. 52 (10.2 mm.) 49 (9.8 mm.) 34 (6.7 mm.) 



Bull III nl us coriaccus, var. a. Seven adults and numerous 

 younger specimens, from the Hacienda de Cuatotolapam, show 

 the dark chestnut band poorh', or even lack it entirely. A few 

 young shells of this form were obtained on the ground in the 

 lowland forests (H, i, a), but the majority were collected from 

 the cleared land (H, ii, b) along the railroad track, in sugar- 

 cane and corn fields, and even in the middle of a road, where 

 they were observed, coming up out of the ground in consider- 

 al.ile numbers, during a rain-storm. This is plainly a deep- 

 burrowing form, that appears to occur in colonies, and which 

 thrives under conditions of cultivation. Most of the specimens 

 were c|uite typical in shape, but others were considerably more 

 slender. Examples measure : 



Altitude Greatest diameter Height aperture Diameter aperture 



15.8 mm. 56 (8.8 mm.) 48 (7.6 mm.) 36 (5.7 mm.) 



15.8 mm. 51 (8.0 mm.) 47 (7.2 mm.) 30 (4.8mm.) 



The radula of this form is shown in figure 3. The entocone 

 is represented by a distinct lamella on most of the inner teeth. 

 The radular formula may be given as : 

 I 15 6 2 I 



C-;L- + - + - + - = 24-i-24. 

 3 2 3 4-f I 



There is no marked differentiation of marginals, but the teeth 

 toward the outside of the radula become smaller, tend to turn 

 inward, and lose the entoconal lamella. 



