TROCHUS. 27 



coarsely granulose in about 5 or 6 spiral series, of which the upper 

 series is most prominent ; periphery rounded ; base a little concave, 

 with about 7 concentric granulose or subgranulose lirse ; aperture 

 strongly lirate within upon the parietal and outer wall, basal margin 

 with four or five teeth ; columella dentate ; umbilical tract nearly 

 smooth or obsoletely spirally plicate. Alt. 30, clinm. 30 mill. 



T. inerossatus Lam., An. su/i* Vni.. vii, 1822, p. 20. Pkilippi, 

 Conchyl. Cab. t. 18, f. 3, Fischer, Coq. Viv. p. 113, t, 37, f. 1. 

 Reeve, Conch. Icon., f. 77. 



Typically narrower, more solid than T. crenifct'iin, with heavier 

 parietal callus and not so strongly tuberculate around the periphery. 

 T. incra8satu8 Phil, mav be a svnonvm of T. creniferus. 



if * * J 



Var. CREXIFERUS Kiener. PL 7. figs. 67, 68. 



This is a form closely related to T. maculatus, T. flammulatus and 

 T. sandwichensis, but more especially to T. incrassatus, and some- 

 what intermediate between these species in characters. It is strong 

 thick and solid ; the form is conical ; the diameter exceeds the alti- 

 tude; the outlines of the spire are slightly convex, the whorls near- 

 ly plan u late, generally a little concave in the middle. The sculpture 

 consists of four series of distinct, clearly cut, rounded granules upon 

 each whorl, of which the upper and lower are elongated, like short 

 folds, and apparently formed by the coalescence of the granules of 

 two rows ; upon the last whorl the sculpture sometimes seems to con- 

 sist of oblique regular rather coarse folds, cut about the median por- 

 tion by three narrow spiral furrows. There is a trace of the very 

 fine secondary sculpture of minute oblique wrinkles upon many 

 specimens, like that of T. flammulatus, but less strongly developed. 

 The folds crenulate the periphery. The base is slightly convex to- 

 ward the outer edge, concave in the middle, concentrically six-lirate, 

 the line rather coarse, sometimes very superficial, and are regularly 

 beaded. The aperture is brilliantly nacreous within ; the outer lip 

 is lirate within ; the parietal wall is lirate, and colored like the base 

 except for a slight deposit of whitish callus ; the basal margin is 

 thick, nearly straight, nearly smooth, or slightly dentate ; the col- 

 umella is oblique, pearly, quadri-dentate ; the umbilical area is 

 funnel-shaped, lined with a heavy white, porcellanous coat, which 

 does not extend within the aperture, nor to the edge of the columella ; 

 it is obviously bi-lirate, one rib revolving at the lower edge and 

 terminating in a denticle at the angle where the columella joins the 

 base, the other sometimes bifid, a little within the cavity, not attain- 



