from the Gulf of California, etc. 383 
umbilical indentation; aperture sub-circular; lip bevelled, sharp, 
blue black; submargin dead white; columella white, acute, with 
two denticles at lower part ; fauces silvery white. 
Axis one and a half inches ; diameter one and one fourth inches. 
Inhabits San Diego. Lieut. Green. 
It has the shape, solidity, size, and coloring of T. fragarioides, Lk. 
lugubris, Lk. It is distinguished by not having its colors arranged 
in bands, in having an umbilical indentation, and two denticles on 
the columella. 
MODULUS DORSUOSUS (Pl XIV. Fig. 12.) 
i depressa, ovato-conica, solida, calearea, ad peripheriam acuta et nodulosa, 
supra obscuré undulato-nodoso, infra conica, spiraliter insculpta ; apertura 
sub-triangularis, labro acuto intus sulcato ; columellá et dente rosaceis; um- 
ilico parvo, profundo. 
Shell small, solid, depressed, ovate conic, dead white, the upper 
whorls as it were eroded, the outer one angulate, flattened or a 
little excavate above, varied with obsolete radiating folds by which 
the periphery is rendered nodulous; the nodules extend somewhat 
on the conical base which is sculptured by about six spiral grooves, 
one of which cuts the nodules. There are sometimes faint traces 
of dusky markings between the tubercles and on the basal ridges. 
Aperture subtriangular, lip sharp, grooved within ; umbilicus small ; 
tooth and columella tinted pale rose-red. 
Jiameters, transverse half an inch; vertical nearly one third of 
an inch. 
Found at Acapulco. Col. Jewett. 
This Species is not mentioned in M. Petit's recent list of the 
species, but it approaches M. obliquus, and also M. duplicatus, both 
of which are described as spirally grooved above, and the former 
Seems to have a sharp periphery. 
CHEMNITZIA TENUICULA (PL XIV. Fig. 15.) 
ns gracillima, lanceolata, nitida, cerina, infra suturam fascescens ; anfr. 10 
Planulatis, tabulatis, longitudinaliter ad 20-plicatis, striis numerosis volventibus 
leviter Secatis; basi modo spiraliter striata; apertura angusta, ovata; labro 
Shell small, elongated lanceolate, turreted, rather solid, shining, 
