64 EPIROBIA. 



Cylindrella apiostoma PFR., P. Z. S., 1856, p. 322 ; Conchyl. 

 Cab., p. 32, pi. 8, f . 3-5 ; Monogr., iv, p. 703 ; vi, 376 ; viii, 435. 

 FISCHER & CROSSE, Miss. Scient. Mex., Moll., i, p. 406, pi. 17, 

 f. 15. SOWERBY, Conch. Icon., xx, pi. 15, f. 129. Epirobia 

 apiostoma Pfr., STREBEL, Beitrag, iv, p. 88, pi. 5, f. 6 (shell), 

 pi. 13, f. 11 (genitalia). Holospira apiostoma Pfr., MARTENS, 

 Biologia, p. 283, pi. 17, f . 4. 



Pfeiffer's description is given above. Strebel, who exam- 

 ined the types in Dohrn 's collection, gives the length of one of 

 them as 16.6, diam. 2.4, length of mouth 2.2 mm., whorls 23. 



The specimen figured by Crosse and Fischer was a little 

 smaller, as are several before me, received from Salle, two of 

 which measure : 



Length 16, diam. hardly 2, longest axis of aperture 1.7 mm. ; 

 whorls 22. 



Length 15%; diam. 2, longest axis of aperture 1.5 mm.; 

 whorls 22. 



However, Strebel's photographic figure of the Pfeifferian 

 type gives a breadth of 2 with a length of 16% mm., with the 

 mouth certainly less than 2 mm. ; so that it would seem certain 

 that his published measurements are erroneous. Those of 

 Pfeiffer, too, indicate diameter and length of mouth as too 

 large for his own figures. 



The apex, as in all the group, is obtuse, and usually a num- 

 ber of the early whorls are very pale colored, as though aban- 

 doned by the viscera. All the whorls are decidedly convex. 

 The free portion of the last whorl is somewhat flattened on its 

 outer and upper surfaces, producing a decidedly ovate or 

 somewhat pear-shaped outline of the aperture, which is quite 

 characteristic. The slender axial tube bears irregular oblique 

 laminae, some of which are smooth or nearly so, while others 

 are coarsely serrate. In the last whorl there are only oblique 

 white veins in the substance of the pillar (pi. 20, fig. 15) . 



E. POLYGYRA (Pfeiffer). PL 20, figs. 11, 16, 17, 18, 19. 



Shell deeply rimate, subulate, thin, fleshy-whitish. Sur- 

 face lustreless, sculptured with arcuate, thread-like riblets 

 separated by spaces of fully double their own width. Whorls 



