102 THE NAUTILUS. 



ened outwardly, broadly dilated at the insertion, partly covering 

 the umbilicus ; parietal film transparent but not very thin. 



Height 12.7, diam. 20 mm. Aperture with peristome 12.7 

 mm. wide; umbilicus 1.7 mm. wide. 



Locality. — Sinaloa, Mexico, Wm. M. Gabb. Type No. 58124 

 A. N. S. P. 



The special features of this species are its narrow umbilicus, 

 very wide last whorl, large aperture and surface free from any 

 trace of spiral incised lines. The apex is slightly worn, but I 

 think I see traces of the same sculpture described for the first 

 whorl of S. i:)eni7\^aris. It is one of the specimens Gabb 

 identified as Helix remondi Tryon — which is quite a different 

 thing. Gabb was a really notable geological explorer, but 

 sometimes he was not fussy over identifications of shells. 



Epiphragmophora ellipsostoma Pilsbry. PL 2, figs. 6. 



Described in Nautilus VIII, p. 81 (1894), but not figured 

 before. The locality given by Gabb, San Juan del Norte, is 

 rather ambiguous. It would be taken for the place so named 

 in Nicaragua were it not that the specimen was stuck on a label 

 with a shell of SonoreJla peninsularis, suggesting a Lower Califor- 

 nian habitat. The malleation and epidermis recall Californian 

 and Peruvian Helices, but no similar species has been taken in 

 Nicaragua. The figures represent the type-specimen, no. 10745 

 A. N. S. P. 



OBSEBVATIONS ON THE UNIO COB, OF CONBAD. 



BY L. S. FRIERSON. 



T. A. Conrad published in 1834, his "New Fresh Water 

 Shells" describing and figuring a number of species. His 

 figures were not very good, and some confusion ever since has 

 been the result. For instance, his figure of U. prasinus is so 

 unlike the figure given by Dr. Lea for his U. schoolcrqfti that the 

 two have been placed as different sub-species in our lists ; yet 

 both figures were drawn from the same identical specimen ! 

 Mr. Conrad figured a shell, (presumably his Unio stramineiis) 

 on plate 7, but he omitted it altogether from the text ! 



