122 AMERICAN MARINE CONCHOLOGY. 



six, last large, with a very obscure keel; axis umbilicated, keeled 

 on the edge. 



Diara. 10 mill. 



Arctic Seas. 



Genus SPIRIALIS, Eydouxand Souleyet. 

 Rev. Zool., 235. 1840. 



1. S. GouLDii, Stimpson. Fig. 254. 



Proc. Bost. Soc. Nat. Hist., iv. 8. 1851. 



Heierofusus balea, Biuney (not Moller), Gould's Invert., edit. ii. 505. 1870. 



Shell ovate-globose, vitreous, veiy thin, pellucid, very light, 



narrowl}'^ and deeply umbilicated ; spire conoid ; whorls seven, 



sculptured by minute, distant, unimpressed, revolving lines ; last 



whorl large ; aperture about equalling the spire, obtuse in front. 



Length 2.5, breadth 1.8 mill. 



Massachusetts Bay. 



2. S. Alexandrt, Yerrill. Fig. 255. 



Am. Journ. Sci., 3d ser. iii. 281. 1873. 

 Ueterofusus retroversus, Biuney (not Fleming), Gould's Invert., edit. ii. 



505. 1870. 

 Spinalis Flemingii? A. Agassiz (not Forbes), Bost. Proc, x. 14. 1865. 



Body-whorl very ventricose ; spire of four whorls, not forming 



half the length of the shell. 



Nahant, Mass. 



Family CLIOXIDvE, Gray. 

 Syu. Brit. ]Mus. 1840. 



Genus CLIONE, Pallas. 

 Spicil Zool., X. 28. 1774. 



1. C. limacina, Phipps. Fig. 256. 



{Clio.) Voy. North Pole, 195. 1774. 



Clio borealis, Brug. Eucyc. Metli. Vers., i. 506. 1792. 



Gelatinous, pellucid, pale-blue; mouth and eud of the body 



scarlet when out of water, hyaline ; wings somewhat triangular ; 



tail acute. 



Portland^ Me., nortJncards. 



Class ACEPHALA. 



Animal without head, always aquatic, contained within a bi- 

 valve-shell, one valve of which is applied to the right and the 

 other to the left side of the bod}-. 



