Mollusca of Dominica. 433 



13. Succinea apjivoximanSj Shuttl. 



14, Cyclotus amethystinus^ n. sp. 

 Testa turbinato-depressa, rubra vel straininea, subdiaphana, spira- 



liter striata, lineae incrementi rugosae ; spira depressa, conoidea ; 



anfr. 5, convex!, infra Iseves, supra (in forma «) spiraliter lirati 



lineis angustioribus quani interstitia eorum (in forma /3 laeves) ; 



umbilicus latus, profundus ; apertura parum obliqua ; peristoma 



simplex, continuum, breviter affixum, margins externo parum 



prominente. 

 Alt. 8| millim., lat. maj. 19, lat. min. 15. 

 Operculum corneum, diapbanum, externe coucavum, interne carti- 



lagineum. 



a. Shell turbinate-depressed, reddish or straw-coloured, sub- 

 diaphanous, spirally striate, the stride of growth generally 

 rather rugose ; spire depressed, conoidal ; whorls 5, convex, 

 smooth beneath, lined above by spiral strige narrower than 

 their interstices, the last scarcely descending anteriorly. Oper- 

 culum horny, diaphanous, concave externally, cartilaginous 

 within, the nucleus projecting internally; with from ten to 

 fourteen very narrow whorls, their rather lamellar outer edges 

 slightly free. 



/3. Smooth, shining, not striate spirally, generally some- 

 what more depressed, deep chestnut or reddish brown ; whorls 

 a little flattened near the suture. Operculum as in a. 



This is a notable species, owing to its operculum, which 

 departs widely from that usual in this genus. In no specimen 

 did it present the least approach to the shelly consistency of 

 the opercula of most Cycloti. The spiral striation of the shell 

 is generally very distinct, but in var. /3 it is altogether want- 

 ing. The present species approaches C. i^opayanus in shape, 

 being, however, a little more depressed ; and it is not closely 

 allied. 



15. Helicina plicatulaj Pfeiffer. 



Some examples of this species are reddish, and some are 



yellow. 



16. Helicina epistilia, n. sp. 



Testa orbiculato-conoidahs, solidiuscula, lineis incrementi striata, 

 rubro-brunnea vel obscure flava ; spira elevata, apex acuminatus; 

 anfr. 5, paulum convexi, inferne applanati ; sutura paululum 

 crenulata, parum descendens ; apertura parva, semiovalis, lata 

 aequo ac alta; peristoma anguste reflexum, parum incrassatum ; 

 callus basalis tenuis, vix distinctus ; columella simplex. 



Alt. 5^ millim., lat. 8|. 



Operculum pallide corneum. 



An orbiculate-conoidal, obscurely yellowish or reddish shell, 



