146 HELIX-ISOMERIA. 



chestnut ; spire obtuse ; whorls 5 to 6, plano-convex, the last sub- 

 acutely carinated, deflexed and constricted anteriorly ; flatly im- 

 pressed on the base ; aperture somewhat squarely ear-shaped ; per- 

 istome thickened, callous, livid-flesh-color, terminations joined by a 

 callous ; basal margin with two small teeth, more or less obsolete. 



(Reeve.} 



Puntophaya, Ecuador. 



H. atrata REEVE, Conch. Icon., f. 549 May, 1852. Isomeria 

 mauritii JOUSSEAUME, Moll. nouv. de la Repub. de 1'Equateur, p. 16 

 (Bull. Soc. Zool. France 1887). 



This form has been commented upon under the last species. It 

 seems to differ from H. atrata Pfr. in being malleated and in having 

 two lip-teeth. Jousseaume (loc. cit.) gives no new information, 

 having apparently not seen the species which he re-names. Hidalgo, 

 regarding Reeve's atrata as a variety of Pfeiffer's shell of the same 

 name, says (Viage al Pacif. p. 13): 



" The figure and description of the Conchologia Iconica of Reeve 

 is different from that of Pfeiffer, agreeing with an example in the 

 collection of Sr. Paz, which presents on the last whorl the irregular 

 depressions of H. cymatodes Pfr. Another specimen has a small 

 tooth on the superior part of the right lip." 



H. CYMATODES Pfeiffer. PI. 46, figs. 24, 25, 26. 



Imperforate, depressed, rather solid, opaque, deep chestnut-colored ; 

 surface shining, arcuately striate, especially beneath the sutures, last 

 1J ivhorls conspicuously indented or malleated above and beneath the 

 periphery, the entire surface microscopically granulated ; spire con- 

 vex, depressed ; apex obtuse ; sutures linear, a trifle impressed ; 

 whorls nearly 5, a little convex, moderately, regularly widening, the 

 last very slightly dilated transversely, depressed, carinated, the 

 carina extending to the peristome, base tumid on its latter third, 

 deeply indented at the axis, whorl abruptly deflexed and constricted 

 behind the peristome ; aperture very oblique, truncate oval, livid in- 

 side ; peristome reflexed, white, upper margin a little arcuate, outer 

 margin curved, with a small denticle in the middle, basal margin 

 straightened, expanded at its insertion over the umbilicus, connect- 

 ing with the upper margin by a white parietal callous; parietal 

 wall bearing a small oblique white tooth. 



Alt. 24, diam. maj. 51, min. 44 mill. (Specimen.) 



Alt. 28, diam. maj. 54, min. 45 mill. (Hidalgo.) 



Alt. 22, diam. maj. 52, min. 42 mill. (Pfeiffer.) 



Alt. 22, diam. maj. 52, rain. 43 mill. (Miller.) 



Ecuador. 



