32 SPIBAXIS. 



species mow known. Besides the forms 1 herein recognized, 

 there are several other species, represented by poor material 

 or single specimens in the 'collections I have studied. 

 a. Grooves widely and irregularly spaced on the last whorl 

 or two. 



b. "Whorls 8 to 10; aperture about one-fourth the total 

 length ; 15 to 16 mm. long, 3.5 to 3.8 wide. 



8. procerus, no. 34. 



bb. Whorls 9 ; aperture contained about 3 l / 2 times in 

 length; 23 x 6.6 mm. S. clava, no. 35. 



bbb. "Whorls 5y 2 to 7; aperture about one-third the 

 length; shell smaller. 



c. Diaim. less than one-third the length. 



d. Length 5 to 7 mm. ; grooves well spaced 



throughout. S. Icrviiisculus, no. 36. 



dd. Length 5 to 7.5 mm. ; grooves crowded 



on spire. 8. pauperculus, no. 37. 



ddd. Length 8 to 11 mm. ; grooves widely 



spaced throughout. 



8. pcrplexus, no. 38. 



c. Diam. more than one-third the length. 

 d. 5.3 x 1.8, atpert. 2.3 mm., 5!/2 Whorls. 



8. 0)1110", no. 39. 

 dd. 4.75 x 1.75, apert. 2 mm. 



S. brevis, no. 40. 



aa. Grooves crowded and regular or nearly so on the later 

 whorls. 



b. Jamaican; small, about 4.5 x 1.25 or 1.3 mm., aper- 

 ture about one-third the total length; very closely 

 striate. 8 to 10 strias in a mm. on face of last whorl. 



c. Last whorl convex. 8. perstriatus, no. 41. 



cc. Last whorl flattened, parallel-sided. 



8. parallelus, no. 42. 



bb. Haitian; small, length 4.2 to 5.6 mm., aperture more 

 than a third the length. 



c. 4.24 x 1.4 mm. with 4% whorls; about 12 

 grooves in one mm. on face of last whorl. 



8. unus, no. 46. 



