﻿PTEROPODA.— Plate I. 



Species 4. (Mus. Brit , &c.) 



Htalj:a tkidestata. 3ija. testa intense fused, ienni, 

 infra pallidiori, postice acute trispinosd ; spinis 

 lateralilms alceformibus, spina temiinali recta, disco 

 inferiori subtrigono, aperturam versus divaricatim 

 subtrilobato ; disco superiori globoso, ad latera 

 marginato ; aperturd trigond, labro rostrate, mar- 

 gine sviguadrilobato. 



The threk-spined Htal«a. Shell deep brown, thin, 

 rather paler underneath, posteriorly sharply 

 three-spined, lateral spines wing-shaped, termi- 

 nal spine straight, lower disc subtrigonal to 

 subtrilobate towards the apertnre ; upper disc 

 globose, bordered at the sides ; apertnre trigonal, 

 outer lip beaked, margin sb'ghtly four-lobed. 



FoRSKAL (Cavolina). 



Hyalcea papilmiacea. Bory St. Vincent. 



Hyaloea ForslaUi. D'Orbigny. 



Hyalcea Pangii. Deshayes. 



Hab. Mediterranean. Great Britain ? 



It is probable that the variety, tig. t>, with white 

 border and appendages, may be the H. papilioiw.cea 

 of St. Vincent. 



Species o. (Mus. Brit.j 



HyaLjEA Cumingii. Eya. tenia trispinosd, jinUidd, 

 tenuissimd, iridescenti, nebulosd, vel pallide suc- 

 cined, quam H. trispinosa magis ohlongd, spinis 

 lateralibus magis approximatis, rostra subtrigono, 

 producto. 



Cuming's Hyal^a. Shell three-spined, pale, very 

 thin, iridescent, clouded, or pale amber, more 

 oblong than Helix trispinosa, lateral spines more 

 approximated, beak subtrigonal, produced. 



Deshayes. MS. Mus. Cuming. 



Hi/akva 7iebulosa. Deshayes (var.) 



Hah. ? 



Of a more oblong form and lighter texture than 

 H. trispinosa, but the difl'erence is not very obvious. 

 There is something in the texture of the pale variety 



giving a cloudy iridescence, which may, however, 

 indicate a real specific distinction. 



Species G. (Fig- a, b, Mus. Brit.) 



Hyal^ia globulosa. Hija. testa trispinosd, ovatd, ven- 

 trlcosd, albd, angustiiisculd, disco ventrali oblique 

 conico, ad apicem rotunda elevato, spinis lateralihns 

 obtusis, swbapproximatis, spina, apicali deflexd, 

 trnncatd, perforata ; aperturd anguste semilunari, 

 labro breviter marginato. 



The globose Hyal^ia. Shell three-spined, ovate, 

 ventricose, white, rather narrow ; ventral disc 

 obliquely conical, roundly raised at the apex, 

 lateral spines obtuse, somewhat approximate, 

 apical spine bent downwards, truncated, per- 

 forated ; aperture narrowly semilunar, outer lip 

 shortly marginated. 



Rang. Proc. Zool. Soc. 



Hah. ? 



7. (Fig. a, b, Mus. Brit.) 



HyaLjEA gibbosa. Hij. testa trispinosd, ovatd, ventri. 

 cosd, albd, angustiHsculd, elongatd, disco ventrali 

 oblique conico, acummatim elevatd, ad unguium 

 elevatum rugatd ; spinis lateralibus approximatis, 

 spind centrali elongatd, leviter deflexd. 



The gibbous Htal.s:a. Shell three-spined, ovate, 

 ventricose, white, rather narrow, elongated ; 

 ventral disc obliquely conical, acuminately ele- 

 vated, wrinkled at the raised angle ; lateral 

 spines approximated, central spine elongated, 

 slightly deflected. 



Rang. D'Orbigny, Voy. Amcr. Merid. 



Hah. ? 



This and the preceding species are swelled and 

 raised at the ventral disc, forming an oblique cone, 

 leaning towards the aperture in each case. In 

 Hyatea globulosa the apex of the cone is rounded. 

 In H. gibbosa it is raised into an acuminated 

 strongly-wrinkled beak. 



