194 



notch. (Immature shells are without the columella-characters). 

 Operculum multispiral. 



Ornament of early spire-whorls consisting of three plain 

 cinguli, the posterior one smaller than the others ; of penultimate 

 whorl wdth a riblet between anterior suture and first cingulus, 

 between first and second, and second and third cinguli ; of last 

 w^horl with seven cinguli on the upper-surface and interposed 

 riblet here and there, base with seven cinguli, with an interposed 

 riblet in the one or two exterior sulci; there is no conspicuous 

 rib margining the umbilical area. The whole surface of the shell 

 (except apical whorls) is sculptured with fine close oblique striae, 

 which pass over the principal cinguli, which occasionally show a 

 tendency to granulation. 



Dimensions of a large specimen: — Height, 6*25; basal 

 diameters, 5*75 and 6-5. 



Localities. — Living at low tide-mark, under stones, Moonta Bay 

 (MM. Maughan and McDougall); off* Rapid Bay Head, in 10 to 12 

 fms. ; off" Corney Point, in 30 fms., and off* Rickaby (Dr. Verco). 



This Euchelus-like shell, wdiich has been known to me for 

 several years, I had thought might be immature ; but it is only 

 recently that I have had the opportunity of studying a large 

 suite of specimens, which jDermits me to alter my opinion. The 

 simplicity of the apertural and umbilical characters combined 

 with those afforded by the ornamentation are such as to render 

 unnecessary a comparison w^ith other species of the genus. 



Thalotia negleeta, spec. nov. PL i., fig. 6. 



I separate under the above name a shelly wdiich has been con- 

 founded with T. chlorostoma wdth w^hich it agrees in its arcuate 

 and truncated columella, but is without the acutely-carinated 

 periphery, and thus establishes a passage from Thalotia to tlie 

 section OdontotrochnSy though it has more of the facies of the 

 latter than the former. 



The columella, as in T. chlorostoma, is sharply defined by a 

 coincident umbilical depression. The species diff*ers by the 

 absence of the supra-sutural carina, its slightly convex whorls, 

 and less elevated spire. 



The whorls, eight in number, have the spiral and transverse 

 ornament, as in T. chlorostoma. The colour is usually brown 

 or yellowish, spotted with wdiite or brown-white blotches, and 

 more or less with white and brown above the suture and on the 

 periphery, rarely unicolorous (greenish-yellow). 



Adult specimens, as shown by the thickened outer lip bevelled 

 to a sharp edge, have been dredged in life on Troubridge Shoal, 

 St. Vincent Gulf, in six fathoms, by Mr. Matthews. Taken 

 abundantly, living and dead, in St. Vincent and Spencer Gulfs 

 at various depths from 5 to 15 fathoms (Dr. Verco). 



