Quartet ly Journal of Conchology. 209 



Hald.; Nematura, Benson; A??inicoIa, Gould and Haldeman; and 

 Tulotoma, Hald.; the latter being described as follows: "Soft parts 

 of animal and lingual dentition unknown. Operculum with the 

 nucleus simple. Shell thick, pointed conic, imperforate. Whorls 

 flattened, nodulous, carinated, with a dark, olivaceous epidermis; 

 peristome thin, continuous." y 



The generic description here given is somewhat faulty, as the p" r . | 

 term "pointed-conic " does not apply to the shells in question, all >*' 

 the species being obtusely-conic, even when the spire is most perfect. ,;'■' -r 

 The epidermis, in all the species, ranges through all varieties of \ A 

 coloration, yellow, green, red and purple tints to black, and the ^ 

 shells are often beautifully banded. The shells of the T. Coosa. ; 

 ensis, are not "imperforate," the peristome is not reflected as in the \v- 

 other species : nevertheless they are but slightly umbilicate. The ,A\f'' y 

 shells of both T. angulata and T. Coosaensis may be described as ' -r^ 

 thm shells with entire propriety: and the latter is very thin for a f 

 species of this family. The description of the operculum is alto- 

 gether faulty, or rather wanting, and, in shells where that organ is 

 so entirely different from that of associate genera of the same 

 family, the difference is worthy of particular notice, especially since, 

 in the species under consideration, it is precisely alike. 



Mr. Binney, probably recognizing these facts, says, "Operculum 

 horny, subtriangular, with a lateral nucleus and concentric strise." 

 This description would read more correctly if semicircular was 

 substituted for "subtriangular", and the following added: Columel- 

 lar margin straight, outwardly reflected, forming an elevated, mai'- 

 ginal fold, along its whole extent. Nucleus central on the columel- 

 lar margin. Operculum increasing by growth in semicircular layers, 

 which overlap each other, so that the outer margin is much the 

 thinnest part. Outer surface rough and scaly; inner bearing a lu- 

 natic cicatrix of attachment, and a narrow, polished line surround- 

 ing it. 



