LUCAPINA. 199 



third of the shell, falling over and enveloping the head and body, 

 its edge simple, not papillose. There is a row of epipodial papillae, 

 about 20 on each side. Dentition unknown. 



Comparisons should be made with the West Coast forms, the soft 

 parts of which I have figured in Proc. Phila. Acad., 1891. 



Species three: elongata, a small, narrow, parallel-sided form; 

 adspersa, wider, larger ; and cancellata, more conical, stained around 

 the hole with black. Numerous shells of all lie before me. 



L. ELONGATA Philippi. PI. G2, figs. 1,2: pi. 36, fig. 31. 



Shell small, narrow, oblong, depressed ; the side margins parallel, 

 length twice the breadth (more or less). Front slope less than half 

 as long as the posterior slope. Sculptured with alternately larger 

 and smaller radiating riblets, with usually some short interstitial 

 threads posteriorly. About 32 to 38 riblets may be counted around 

 the perforation. These radiating riblets are crossed by elevated 

 concentric threads, about 8 to 10 of which may be counted on each 

 side of the perforation. Length of hole from one-sixth to one-sev- 

 enth the length of shell. 



Yellowish or white, irregularly freckled with brown. Inside 

 whitish with radiating whiter lines, the hole-callus white, truncated 

 posteriorly. Length 13, breadth 6 J, alt. 2j mill. 



St. Thomas, West Indies. 



F. elongata Phil., Abbild. u. Beschreib., etc., ii, p. 33, Fissurella, 

 t. 1, f. 2. (Oct., 1845).— Reeve, Conch. Icon. f. 110.— Sowerby, 

 Thes. p. 201, f. 185.— Arango, Fauna Mai. Cubana, p. 228. 



Closely allied to the following, but narrower, the orifice more 

 anterior, the rays interrupted into sparsely scattered dots and short 

 lines. Arango seems in doubt about his identification. He records 

 the species from Cuba and Guadalupe. The specimens before me 

 are from St Thomas, collected by Robert Swift. 



L. adspersa Philippi. PI. G2, figs. G, 7 ; pi. 38, fig. 69. 



Shell oblong, depressed-conical, the front slope more than half 

 the length of the posterior slope; sculptured with radiating alter- 

 nately larger and smaller riblets crossed by numerous concentric 

 raised threads. Perforation oval, about one-seventh the length of 

 shell. 



White, brown-tinged or greenish-yellow, with 7-9 broad rays 

 varying from flesh-colored to ashen or olive-brown. These rays are 

 interrupted or broken into dots and spots in many specimens. In- 



