11 E L I C I N A. 



Genus HPiLICINA Lamarrk. 



Testa tenrstre, kelici/oiinis, conica, lenticularis, met 



globosa ; apertur<r tnargine intemo rectiuscido, 



manjine externa pkrumqite rejhxo vcl iiicrassato. 



Operculum concent i-i cum, testaceum vel coi-neum, oblique 



semilunari vel subquadralum, nucleo subceatrali. 

 Slicll terrestrial, helieiforiii, conicul, lenticular or 

 globose ; inner edge of aperture ratlier straight. 

 outer margin generally reflected or thickened. 

 Operculum concentric, shelly or horny, obli(iuely semi- 

 lunar or subquadrate, with nearly central nucleus. 

 It is difficult to accept as useful the numerous 

 generic divisions into which the species of this genus 

 have been .separated. The pas.siiges from the conical to 

 the globose, the globose to the lenticular, the notched to 

 the entire columella, the impercei)tible to the thick 

 rounded callus, the rounded to the angular, and thence 

 to the keeled body-wliorl, are made bv almost impercep- 

 tible gradations. That being the case, it is impossible to 

 define snch genera as Trochatella, Alcudin, Lucidella, 

 <tc., so as to distinguish them from each other, and 

 from llelirina ; while, on the other hand, they unitedly 

 form a genus of varying forms, but fairly included in 

 one genus as defined above. 



The llelicina abound more on islands than on con- 

 tinents, jireterring the tropics. Cuba, the West Indian 

 Islands, especially Jamaica, the Philijjpines, and the 

 Pacific Islands are among tlieir favourite habitats, 

 although the tropical, and even the nortliern parts of 

 the .American continent ]iroduce many species. The 

 rapid increase in the nuniber of known species that has 

 t.aken place in this genus is very remarkable. In 1842 

 Mr. Sowerby publi.shed 7;i species, a large proportion 

 of which were then recent discoveries; and in 18GG his 

 2nd Monograph with 270 species. In the present 

 work we describe 310. 



I Ml 



Brit. ) 



IIki.icina DissiMi la.ns. lltl. tesld depressd, fusco- 

 rubefcenti, concentriw striata ; spird depresso- 

 contcd, anjractibus parcis, paticis, ultimo anfractu 

 fublenticuluri, medio obtusissimc aiiffulato, callo veii- 

 trali tumidiitaculo, columella aculeatd. obliqud ; labio 

 externo amjiielo, reflexo, luteo, supcrne senuatim de- 

 press), in/id ad colunidlamjis^urd iiirisd emarginato. 



The dissimi:l.\tis(: Helicina. Shell depressed, reddish- 

 brown, concentrically striated ; spire depressed- 



conical, whorls small, few, last whorl rather len- 

 ticular, very obtusely angular in the middle ; 

 ventral callus rather thin, columella aculeated, 

 oblique ; outer lip narrow, reflected, yellow, 

 sinuously depressed above, notched with an in- 

 cised figure below at the columella. 



Poet. Mem. II., p. 35, t. 4, f. C, 7. 



Hah. Cuba. 



Species 2. (Fig. a, b, Mus. Nobis.) 



Helicina si'bmahginata. Hel. test(tgloh(Mi-siihd>'j>ns.-<,i. 

 fused, vel rubra ad sutiiram /ilcniuiqnc /iitm 

 marginatd, spiraliter punctatn-slrinta ; sjiiri'i sub- 

 conicd, an/ractibus convexis, majusculis : apice 

 obtuso ; ultitno anfractu inflato, medio fihsmre 

 angulalo ; callo ventrali magiiu, albo, tumido, 

 cohimelld obliqud, aculeatd ; labio externo luteo, 

 crasso, ad columellam infra tmarginato. 



TUE SUBMAItGINATEI) HlCLICINA. Shell globosc-sub- 



depressed, bruwii, or red generally bordered at 

 the suture with yellow, spirally puncture-striated, 

 spire rather conical, with rather large convex 

 wliorls; apex obtuso; last whorl inflated, obscurely 

 angular in the middle; ventral callus large, white, 

 tumid : columella oblique, aculeated ; outer li]) 

 yellow, thick, notched below at the columella. 



Gli.vY. Zool. .luuni. i. p. CS, t. fi, r. II. 



Helicina rubra, I'lVilicr. 



Ilab. Cuba. 



Species 3. i" Fig. a, h, Mus Nobis.) 



IIelicis.\ Sagkai.aJs'a. Hel. testa mcgiiti, crussd, siib- 

 angulatd, fused, epidennide viridi iuterduui induttl : 

 spird depresso-conicd, apice obtuso, anfractihvs 

 convexis, callo ventrali exjianso, inrrassnlo, cnluiuilli'i 

 obtuse aculeatd. ; labio externo albo, rejlexo, ad 

 columellam infrd emarginato. 



The Sagha Helicina. Shell large, thick, rather 

 angular, brown, covered sometimes with a green 

 epidermis ; spire depressed-conical, apex obtuse, 

 whorls convex, ventral callus expanded, thickened, 

 columella obtusely aculeate; outer lip white, re- 

 flected, notched below at the columella. 



OiiBlGNy. Mollusques de I'lsle Cuba. 



Helicina Jennnereti ? Pfeiffer. 



Hab. Cuba. 



February, 1874. 



