36 SPIRAXIS. 



Bost. Soc. N. H. ii, 1845, p. 13. PPB., Monogr. ii, 159; iii, 

 394. 



This is the senior species of 'a group of very closely related 

 forms. The type lot of B. Iccviusculus in Adams' collection is 

 mixed, containing four specimens agreeing with the diagnosis, 

 together with four S. pauperculus and several other forms. 

 From the dimensions and other characters it is clear that 

 the shells drawn in fig. 43 and described above served as the 

 original type. The species is very -closely related to S. pau- 

 perculus 'and S. aberrans, but it has fewer grooves on the 

 spire than the former, and the last whorl is perceptibly less 

 swollen. 



The specimens before me from Braco are rather small, 

 about 4.9 x 1.5 mm., with S 1 /^ whorls. The narrowest seen 

 measures 5.2 x 1.5 mm. with fully 5y 2 whorls. The largest 

 shell of a small series from Bogwalk measures 7 x 1.9 mm., 

 aperture 2.2 mm., with 6^/2 whorls; and the largest Iccvius- 

 culus seen is 7.9 x 1.9 mm., aperture 2.4 mm., with GI/O whorls. 



It is not an uncommon species, some ten lots from various 

 sources being before me, most of them unfortunately with- 

 out exact locality. The description of the synonymous 

 B. aberrans Pfr. follows. 



Bulimus aberrans Pfeiffer. (PL 4, figs. 45, 49). 



Shell subulate, thin, glossy, marked with regularly distant 

 impressed longitudinal lines; pale amber colored, sparsely 

 ornamented with narrow, oblique reddish streaks. Spire sub- 

 ulate, the apex rather acute, suture lightly crenulate. Whorls 

 7, flattened, the last one-third the length. Columella callous, 

 twisted-subtrun'cate. Aperture oblong, the peristome simple. 

 Length 7, diam. 2, 'aperture 2.3 x 1 mm. P/V.). Jamaica 

 (Grosse in Cuming coll.). 



Achatina aberrans PFR.,, Proc. Zool. Soic. 1845, p. 138 ; 

 Monogr. ii, p. 270; Oonchyl. Cab. p. 355, pi. 29, f. 20, 21.- 

 REEVE, Conch. Icon, v, pi. 20, f. 110. Spiraxis aberrans C. B. 

 ADAMS, Contrib. to Conch, no. 6, p. 88 (March, 1850) ; prob- 

 ably of GLOYNE, Journ. de Conchyl. 1875, p. 120 (parishes 

 of Manchester, St. Ann and St. Andrew). S. aberrans var. 

 unicolor C. B. ADAMS, Contrib. no. 9, p. 168 (1851). 



