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. lu(]uillensi8$HUTT,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, 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 GMEI,., 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. (semu 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 carinated in all of the sections, although many species are round- 



