HELIX. 75 



beneath the sutures, and paler there, rounded or flattened at the 

 periphery, and showing trace of a carina, sometimes very obsoletely 

 spirally silicate on the base ; aperture quite oblique, slightly deflected 

 above, bluish within ; peristome expanded, white ; columella oblique, 

 rather wide, dilated and adnate at the place of the umbilicus. 



Alt. 34, diam. maj. 35, min. 31 mill. ; alt. 30, diam. maj. 35 mill. 



Sierra de Luquillo, Porto Rico. 



H. luquillensisSHUTT,Diagn. n. Moll., 6, p. 132 (1854) REEVE, 

 Conch. Icon., f. 1274. PFR., Monogr., iv, p. 207. 



Smaller than the preceding forms, with higher spire more distinct 

 sculpture, etc. 



' * * * 



Shell large, globular, dark-colored, with a few broad light bands; 

 whorls few; aperture very large. (Liocheila.') 



H. JAMAICENSIS Gmelin. PI. 5, figs. 48-50. 



Imperforate, large, globose, solid, opaque, slightly shining, light 

 chestnut-brown or olive-brown to chocolate colored, with one to 

 three ill-defined light yellowish spiral bands about the middle of the 

 whorl, spire and apex purplish, first two whorls smooth, glossy, the 

 remainder lightly wrinkled by growth-lines and covered with a fine, 

 dense, very oblique corrugation ; spire short, apex obtuse; whorls 

 3 J, the last very large, globose, gently descending anteriorly ; aper- 

 ture large, oblique, irregularly oval, livid and showing lighter bands 

 within ; peristome thickened, subexpanded, pinkish, columella 

 slightly concave, white at the insertion, dilated over the umbilical 

 and parietal tracts. Alt. 50-53, diam. 55 mill. 



Jamaica. 



H. jamaicensis GMEL., Syst. Nat. xiii, p. 3644. FER., Hist., t. 9 

 B, f. 10, t. 14, f. 6-9 ; and of authors generally. (H. pulla GMEL., 

 Syst. Nat. xiii, p. 3650 ?). 



A well-known species, of somewhat uncertain systematic position. 

 It seems to me more nearly allied to Parthena than to Thelidomus. 



Group XIII. CARACOLUS Montf. (senm latiore.) 



The group Caracolus, in the broad sense in which that name is 

 used here, consists of about ten sections, which are not only similar 

 in shell-characters, but also in anatomy, as far as is known. The 

 shell is generally large, orbicular, dark colored, with a tendency to 

 be cari nated in all of the sections, although many species are round- 



