BRACHYPODELLA, JAMAICAN. 93 



versely ovate, the lip reflexed, channelled within at the nar- 

 rower, outer margin. Axis slender and straight. 



Length 7.5, diam. 2.3 mm., whorls 8. 



Length 9, diam. 2.3 mm., whorls 8%. 



Length 8.2, diam. 2.2 mm., whorls 9 (Adams). 



Jamaica: in the south, from the parish of Manchester to 

 St. Thomas, inland to Clarendon Park and Bogwalk (Jarvis, 

 Henderson) ; Mt. Diablo, in St. Ann (Henderson & Simp- 

 son). Also reported from Jeremie, Haiti (Weinland). 



Cyl. seminuda C. B. AD., Proc. Bost. Soc. N. H., 1845, p. 

 14. PHILIPPI, Abbild., ii, p. 51, pi. 2, f. 16. PFR., Monogr., 

 ii, p. 380 ; Conchyl. Cab., p. 46, pi. 5, f . 12-14. SOWERBY, C. 

 Icon., xx, pi. 5, f. 46. GLOYNE, J. de Conchyl., 1875, p. 122 

 (Long Mt. and Yallahs). BLAND & BINNEY, Amer. Journ. 

 Conch., vii, p. 184 (teeth). WEINLAND, Jahrb. D. Malak. 

 Ges., vii, 1880, p. 358 (occurrence in Haiti). HENDERSON, 

 Nautilus, viii, p. 20, no. 100. Cyl. minuda Ad., RUSH, Naut- 

 ilus, v, p. 69, no. 119. 



The type originally described by Adams was the least aber- 

 rant form of the species, shown nrfig. 41 (Clarendon Park, 

 western Clarendon). Such shells occur at many other locali- 

 ties, with variously divergent forms, so that the latter seem to 

 be merely extremes linked together in a continuous chain of 

 variations, though certain forms may predominate in some 

 places. The typical form resembles B. robertsi, but has in- 

 variably deeper sutures. The most northern point is Mt. 

 Diablo, where it was found by Henderson and Simpson, a 

 locality out of the ordinary range as mapped by Mr. Jarvis. 



In some specimens the whorls become more shouldered, more 

 contracted below, and the basal series of short riblets disap- 

 pears except on the earliest whorls and the neck (fig. 42, 

 Clarendon Park), leaving the whorls smooth except for a 

 diadem of short riblets. This form occurs at Watermount, St. 

 Catherine and Good Hope, St. Andrew (Jarvis), Mt. Diablo 

 (Henderson), and other places, usually intergrading with the 

 typical form. 



Another incipient variety (fig. 44) is similar to the preced- 

 ing in shape, but the riblets are strong and continuous to the 



