160 , TUflBINELLID^. 



callous, spread over the body-whorl, outer lip reflected, not den- 

 ticulate or striated. 



In Neritula the last whorl is depressed and extends over the 

 penultiraate whorl, nearly covering and concealing the spire, 

 which consequently appears very obtuse. The animal has a bifid 

 tail, and operculum similar to Nassa. H. and A. Adams' genus 

 Teinostoma was originally placed next to Neritula, in their 

 " Genera ;" subsequently they removed it to the Rotellidse. 



Desmoulea, Gray. 



Distr. — 6 sp. Senegal, Cape of Good Hope, Japan. D. ahbre- 

 viata, Wood (lii, 100). 



Shell ovate-globose, covered with a downy epidermis ; spire 

 short, conical, apex papillary; whorls depressed ; aperture ovate; 

 inner lip thickened, with a ridge posteriorly ; outer lip con- 

 tracted, thickened externally, plicated internally. Dentition 

 unknown. 



Desmoulea is remarkable for its obtuse apex and solid growth, 

 much resembling some species of Cassididse ; when in fine con- 

 dition, the shell is clothed with a velvety epidermis, but most 

 cabinet specimens are denuded of this. The animal is unfortu- 

 nately unknown, and therefore the systematic position of the 

 genus remains somewhat uncertain — for, whilst some species 

 connect closely with Nassa, the revolving sculpture, globose 

 form, sunken suture and mouth of others are suggestive of 

 Semicassis. 



Family TIJRBINELLID^. 



This group includes a few ponderous tropical species, allied 

 in the characters of the mouth, and in general form and orna- 

 mentation, to the Peristerniinse on the one hand, whilst in size 

 they approach the Yolutidse. The plications on the middle of 

 the pillar are rather distant, narrow, high, and transverse, whilst 

 in Fasciolariinse they are situated lower, are not so prominent, 

 and oblique in direction. The epidermis is frequently persistent. 



The animal (of Yasum) is slow-moving, timid and inactive, 

 shrinking quickly within the shell on the slightest alarm. The 

 operculum is ovate, acute, with an apical nucleus ; it is very 

 thick, claw-like, and partially free at the hind-part. The denti- 

 tion (x, 14) resembles somewhat that of the Buccinid^e, differing 

 in the lateral teeth ; it differs widely from the Nassidse, and 

 quite as much from that of the Fasciolariinte or Peristerniinse. 



TuRBiNELLA, Lam. 

 Etym. — Diminutive of turbo, a top. 

 Syn. — Mazza, Klein. Rapum, Swains. 



