THE NAUTILUS. 91 



entire, conic, with very regular outlines. Wliorls 12-13, convex, 

 regularly increasing, furnished with small warts, becoming obsolete 

 at the base of each whorl and disappearing on the two last ones and 

 sculptured with fine incised spiral sulci more crowded towards the 

 base of the shell. Suture impressed, canaliculate on the last volu- 

 tions. Body whorl broadly oval, rounded, often more convex below 

 its middle. Aperture oval, angular above, not much effuse nor 

 oblique, scarcely sinuous, livid within. Columellar edge thick, 

 regularly arched. Operculum as usual in the genus. 



Long. 30, breadth 10, height of aperture 9 mill. 



Island of Vate, New Hebrides (E. L. Layard). 



This has been submitted for identification to Dr. A. Brot, the 

 regretted author of many papers on Me/aniang and he wrote me that 

 he received the same shell from Dr. W. D. Hartnian under the 

 erroneous name of Melanin ntnriei Gass. He was unacquainted 

 with the shell from Vate and thought it may prove to be an un- 

 ilcscribed species, so that I venture to give a name to it, under Dr. 

 Brot's undisputed authority. 



Neritina coccinea Anc. 



Shell solid, oblong, not shining, reddish-yellow, without markings, 

 tinged with orange near the aperture, finely striated, not spirally 

 .sculptured, convex but not globose. Spire distinct, obtuse, lateral, 

 entire, consisting of two whorls only, very rapidly increasing, the 

 last one very large, transversely oval. Suture linear. Aperture 

 oblique, with the superior edge long and elliptical connected with 

 the basal by a large flat and thick callosity of a dull whitish or livid 

 color. Margins not remote. Outer margin acute. Septal area 

 without teeth. Operculum red, thin. 



Diam. 6-1, height 5, do. of aperture 4; mill. 



Island of Vate, New Hebrides (E. L. Layard). 



This very pretty little species is quite different from any one I 

 know of. It may perhaps be allied to Pease's rubida, from Tahiti, 

 but is very much larger. 



NEW AMERICAN UNIO. 



BY WM. A. MARSH, ALEDO, MERCER CO., ILLINOIS. 



Unio Askewi, new specie?. 



Shell smooth, subrotund, somewhat inflated, inequilateral ; sides 

 slightly constricted, rounded before, subtruncate posteriorly, with 



