HELIX. 



Plate XVIII. 



Species 73. (Fig. a, b, c, Mus. Ciiiniiig.) 



Helix Roissyana. Hel. testa imperforata, subglobosa, 

 crassittsculd, lavi, varie culoratd, epiJenuiJe hydro- 

 phand plerumque obdiicta ; spird oblusissinm ; anfrac- 

 libiis giiiiujiie, conveximcuUs, ultimo ventricoso ; colu- 

 mella decUm, laliuscidd, plana ; apertnrd siiblunari, 

 intui alba; peridomaie expanso, nigro-marginato. 



Roissy's Helix. Sliell imperforated, subglobose, rather 

 thick, smooth, variously coloured, generally covered 

 with a hydrophauous epidermis ; spire very obtuse ; 

 whorls five, rather convex, the last ventricose ; colu- 

 mella slantin|.(, rather broad, flat ; aperture sublunar, 

 white within; lip expanded, edged with black. 



Ferussac, Hist. Moll. pi. 104. f. 2, 3. 



Hab. Island of Mindoro, Philippines ; Cuming. 



The colouring, though variously disposed, is mostly of 



a dark burnt chestnut. 



Species 74. (Mus. Cuming.) 



Helix unica. Hel. testa imperforatd, globoid, solidius- 

 culd, oblique siriatuld, albidd ; suturd profutidd ; an- 

 fraclibun quiiiqui; ad sex, injlalis, supremii planius- 

 culis; colm/u-lld profuiide intranie, arcuatd, subcanali- 

 culatd; aperturd perobliqud, subcirculari, intus alba; 

 peristonwte late expanso, inttts fulvido, nmrginibus 

 approximati^, basali iucrasiato. 



TuE UNIQUE Helix. Shell impcribrated, globose, rather 

 solid, obliquely striated, white ; suture deep ; whorls 

 five to six, inflated, the uppermost rather flat ; colu- 

 mella entering deeply, arched, slightly channelled ; 

 aperture very oblique, nearly circular, white within ; 

 lip broadly expanded, fulvous internally, margins 

 approximated, basal margin thickened. 



Pfeiffer, Pro. Zool. Soc. 1842, p. 151. 



Hab. Samboanga, Island of Mindanao, Philippines; 

 Cuming. 



Mr. Cuming possesses oidy a worn discoloured spe- 

 cimen of this species. It is verj- distinct in form ; parti- 

 cularlv as regards the roundness of the lower whorls. 



Species 75. (Fig. a, b, Mus. Ctiming.) 



Helix matrielis. Hel. tesld imperforald, globoso-de- 



pressd, tenuiusculii, oblique striata, nigricante, epider- 



mide fusco-cinered hydrophand indutd ; ared cohwiel- 



lari nitidi luted, fascia nigricante circumdald ; spird 



parum elala ; sutnrd ttrvi ; anfrartibut quatiwr, lu- 

 preniin complanati» ; columella oblique ralidi (inter- 

 dmu obsoMius) dental d, exlrorsum dilalald, bninned ,■ 

 aperturd snblrapezoidali, intus licidd ; peri>lo)nale in- 

 crassalo, expanso, brunneo-marginato. 



The allied Helix. Shell imperforated, globosely de- 

 pressed, rather thin, obliquely striated, blackish, 

 covered with a brown-ash hydrophauous epidermis ; 

 area round the columella shining yellow, surrounded 

 with a blackish baud ; spire but little raised ; suture 

 smooth; whorls four, the uppermost smooth ; colu- 

 mella obliquely strongly toothed, the tooth beiog 

 sometimes rather obsolete, dilated outwardly, brown ; 

 aperture subtrapeziform, livid within ; lip thickened, 

 expanded, edged with brown. 



SowERBY, Pro. Zool. Soc. 1841, p. 24. 



Hab. Island of Mindanao, Philippines ; Cuming. 



The yellowish colouring about the area of the columella 

 is derived from a thin homy epidermis which covers this 

 part, differing from the hydrophauous epidermis which 

 terminates with the encircling dark band. 



Species 76. (Mus. Cuming.) 



Helix Montfortiana. Hel. tesld imperforald, lurbi- 

 natd, crassd, ponderosd, nigricanti-rufd, epidermide 

 fusco-cinered hydrophand indutd ; spird cnnoidrd, 

 apice violaceo-purpurascente, nudd, nitidd, obtusd ; 

 anfractibus quatuor ad quinque, tiz conveziusculit, 

 ultimo angulato, angulo antic!- eranescente ,- columella 

 declici, callosd, albd, basi subdentatd ; aperturd suhlr- 

 tragond, intun nilide alia; perixtomale breviter rr- 

 flexo, nigro-fusco limhato. 



Montfort's Helix. Shell impcrforate<l, turbinnted, 

 thick, ponderous, blackish-red, covered with a brown- 

 ash hydrophauous epidermis ; spire conoid, a|>cx ob- 

 tuse, naked, violet -purple ; whorls four to five, but 

 little convex, last whorl angled, angle disap|M'aring 

 towards the front ; columella slanting, callous, white, 

 slightly toothed at the base; aperture somewhat 

 square, white and shiiiiug within ; lip shortly re- 

 flected, edged with black-brown. 



Pfeiffer, Pro. Zool. Soc. 1846, p. 3S. 



Ilnb. Philippine Islands ; Cuming. 



A short, Trochus-shaped, rather solid species, allied to 



H. carbonaria. 



Mav, 1S51. 



