NERITINA, 



Ge 



NERITINA, La 



Testa subglobosa, ep'nJermide oiivaci'd plcniimpif iiidufii, 

 spird pared, lalerali, raro exsertd ; anfractibus nunc 

 lavilius, nunc spinis coronatis ; ared columellari plana, 

 sape perampld, wargine inlcgrn ; npiniiirdscmirotundd, 

 labro plus minus dlffuso, iiilrrdinii nlrinqiie dilaialo. 

 Operculum testaceum, seiniofalHiii, apjii'iullce laterall 

 acuta iuHiructum. 

 Shell subglobose, generally covered with an olive epider- 

 mis, spire small, lateral, seldom exserted ; whorls 

 sometimes smooth, sometimes coronated ; columellar 

 area flat, often rather large, entire at the margin ; 

 apertnre semicircnlar, lip more or less diffused, some- 

 times dilated on both sides. Operculum testaceous, 

 semiovate, furnished with a sharp lateral piece. 

 The NerltiucB, or Freshwater Nerites, are distinguished 

 from the Nerilcc proper, or Marine Nerites, chiefly by their 

 more gloomy aspect, thinner substance, and absence of 

 sculpture and of columellar teeth ; there are, nevertheless, 

 some species of extremely brilliant colouring, and some 

 characterized by a conspicuous variously developed crown 

 of spines. Considerable attention has been given to this 

 genus by M. llecluz, and by Mr. G. B. Sowerby, jnu., 

 both in his ' Conchological Illustrations ' and in bis ' The- 

 saurus Conchyliorum;' but the additions made to the species 

 from various sources during the last five years by Mr. 

 Cuming, have increased the number one-half, and rendered 

 a further monograph desirable. 



The NerUiiue are chiefly inhabitants of the Old World, 

 ranging from our own continent and islands through the 

 islands of the Pacific and Eastern Seas to Australia and 

 New Zealand. In the New hemisphere the genus is re- 

 presented mainly in the streams of the West Indies aud 

 Central America. 



Species 1. (Fig. a, b, Mus. Cuming.) 



Neeitina canalis. Ner. testa oblongo-ovatd, subtus con- 

 cavo-depressd, spird parvd, fere occultd, arifractibus 

 convexis, angustis, ared columellari perampld, ad latus 

 cunaliculald ; caruleo-nigrd, ared columellari san- 

 guineo tiitctd. 



The channelled Neritina. Shell oblong ovate, con- 

 cavely dejiressed beneath, spire small, almost hidden, 

 whorls convex, narrow, columellar area very large, 

 channelled at the side ; blue-blaek% columellar area 

 blood-stained. 



SowEKBY, Tankerville Catalogue, p. U, no. 1094. 

 llab. Tahiti (on stones in a rivulet) ; Cuming. 



Of a compressly expanded form, with a very large coin 

 mellar area more or less stained with blood-red. 



Species i. (Fig. u, h, JIus. Cuming.) 



Neeitina olivacea. Ner. testd oblongo-ovatd, subgib- 

 bosd, solidd, spird convexo-pland, fere obsoletd, aufrac- 

 tibus rotundatis, promiscue concentrice striatis, area 

 columellari latiusculd, declivi, mbcallosd ; sordidi 

 olioaced, ared columellari carulescente-albd. 



The olive Neeitina. Shell oblong ovate, rather gib- 

 bous, solid, spire convexly flattened, almost obsolete, 

 whorls rounded, promiscuously concentrically striated, 

 columellar area rather broad, slanting, somewhat cal- 

 lous ; dark olive, columellar area bluish-white. 



Le Guillou, Revue Zool. Cuvierienne, 18U, p. 3I+. 

 Ner i la sol Ida., Recluz. 



Hub. Island of Luzon, Philippines (on stones in a rapid 

 river) ; Cuming. 



Chiefly distinguished by its gibbous, solid, oblong form, 

 the spire being almost obsolete. 



Species 3. (Fig. a, b, Mus. Cuming.) 



Neritina labiosa. Ner. festd orato-globosd, spird parvd, 

 impressd, anfrarlihtix com-i'.rix, riiiiuso-slriiilis, prope 

 spirum contradi^, nr-^ii'i npninniui ruliiiidido-ex- 

 pansis, ared cohihiilhiri luupld, lull: rxfarutii ; oliva- 

 ceo-pi.ridi, lineis ft in-aciilis nigris jiivtd, iulus san- 

 guineo tinctd. 

 The full-lipped Neritina. Shell ovately globose, 

 spire small, impressed, whorls convex, roughly stri- 

 ated, contracted near the spire, towards the aperture 

 rotundately expanded, columellar area large, broadly 

 excavated ; olive-green, painted with black lines and 

 spots, interior tinged with blood-red. 

 Sowerby, Conch. Illustrations, f. 48. 

 Hab. Island of Luzon, Philippines (on stones in a rapid 

 river) ; Cuming. 

 This fine species, first collected in the Philippine lsla^d^ 

 by ]Mr. Cuming, is chiefly distinguished by its bold circu- 

 larly expanded aperture. 



