MAZATLAN UNIVALVES 253 



322. Ethalia amplectans, n. s. 



E. t. minima, planata, diaphand, nitidissiind ; anfractibus 

 iii, plajiatis, peritremati rotundato ; callositate liaud parvd, 

 umhilicum vix iegente,juxta labium 2:)lanatd, semilunatd ; labro 

 acuto, supra anfractum penultimum dilatato ; infra suturam 

 haud impressam callositate, suturam fallacem extus simulante ; 

 apei^turd rotundatd. 



As it is barely possible that this sbell may be the young of 

 Teinostoma ami)lectans, the same Specific name has been given. 

 It differs however in the much smaller size of the callosity, 

 which in this shell displaj^s a broad, semi-lunate planation at 

 the columella, which appears characteristic of the species. 

 Long. -016, lat. -Qi by -032, div. 180". 



Sab. — Mazatlan ; 4 sp. off Spoudylus ; ISpool Col. 



Tablet 1173 contaius the freshest specimen. 



Gentjs TEIN"0ST0:\IA, a. Ad. 



Froc. Zool. Soc. 1853, p. 183.— JT. ^" A. Ad. Gen. vol. i. p. 122. 



Testa spird depressd, polltd, anfractibus rapide augentibus ; 

 regione umhilicali callosd ; aperturd product d. elongatd, ab axi 

 remotd ; interstitio calloso ; peritremati axin versus rotundato, 

 ad pcripheriam, iuterdum angulato. 



Shell EoteUoidi vvith a greatly produced month and eallu?. 

 It resembles Cyclops among the Nassida', and in the appear- 

 ance of the base reminds the observer of Streptaxis and 

 Anostoma among the Helicidc©. Having been described (in 

 English only) from a single species (T. politum, St. Elena, 

 8 fm. Cuming,) some of the characters before given may here- 

 after prove to be only specific. 



323. Teinostoma amplectans, n. s. 



T. t. parvd, albd, planatd, Icevi ; peritremati rotundatd ; 

 callositate spirali umbilieum tegentc, labium versus subplanatd, 

 supra parietem intus suturam decurrente ; apei-turd rotundatd; 

 labro supra anfractum penultimum reflecto ; suturd haud' 

 impressd. 



Although the shells described above as Ethalia may possibly 

 be the young of this species ; yet, as thej^ were all of the same 

 June 1856. y 



