300 TROCHIDiE. 



Sower"by as Margarita undulata, Coutliouy as Turbo 

 incarnatus, and Brown as Trochus inflatus. 



3. T. ama'bilis^, Jeffreys. 



Body of a creamy-white hue, faintly speckled or tinged 

 with yellowish-brown : imUial lappets small : head prominent 

 and wedge-shaped at its extremity, which is finely and deeply 

 fringed by about 20 digitations or points of different 

 lengths and sizes, those in front being the largest ; it is semi- 

 circular in front, and expansile like the foot of Nucida or Leda : 

 mouth lobed : tentacles fihform, remarkably long, and tapering 

 to a fine point ; they are flexible and exquisitely setose : eyes 

 conspicuous, set on short offsets : foot lanceolate, squarish in 

 front, on each side of which it is furnished with two long 

 conical processes, which project at a right angle to the tenta- 

 cles ; it is sharp-pointed behind, and has a prominent trian- 

 gular ridge, extending from the posterior edge of the opercular 

 lobe to the tail : appendages 3 on each side, issuing fi'om 

 beneath the opercular lobe, and between these are a few small 

 papillae ; the two lateral filaments in front are ciliated, and 

 resemble a second pair of shorter tentacles ; the foot is capa- 

 ble of being expanded to a size double that of the shell, so as 

 to form a broad and solid fulcrum. 



Shell pyramidal, moderately solid, semitransparent, of a 

 pearly and partially iridescent lustre: sculpture,t^o spiral ridges 

 or keels on the upper part of each of the last three or four 

 whorls, and one on the upper part of the next or smaller 

 whorl, besides several finer but irregular ridges on the base of 

 the last or largest whorl, and numerous minute spiral striae 

 between all the ridges ; the principal ridges are placed near 

 the suture of each whorl, both above and below, leaving a 

 broad flattened space in the middle and a narrow excavated 

 space below the sutui'e, thus imparting a tower-like appear- 

 ance to the shell ; the upper whorls are also marked with nu- 

 merous short and fine longitudinal ribs, which cross the ridges 

 and make them crenellated : colour pure pearl-white : spire 

 elevated ; apex semiglobose, prominent and slightly tmsted : 

 whorls 7, gradually increasing in size : suture very distinct : 

 mouth nearly circular, but angulated or somewhat notched 



* LoTelv. 



