22 AMERICAN MARINE CONCHOLOGY. 



Subgenus Admete, Kroyer. 



Moller, Naturliist. Tidskr., iv. 88. 1843. 



Shell ovate, thin, covered with an epidermis; spire acute, last 



whorl ventricose ; aperture oval, chanelled anteriorly; columella 



with a few obsolete rudilneutary folds; outer lip thin, simple, 



acute. 



This group appears to represent Cancellaria in the northern 

 seas in the same manner that Trophon represents 3Iurex, and 

 Bela certain species of Mangelia. 



2. C. viRiDULA, Fabricius. Fig. 24. 



(Tritonium.) Fauna Groeulandica, 403. 1780. 

 Cancellaria buccinoides, Couthony, Bost. Journ. Nat. Hist., ii. 105, t. 3, f. 3. 

 Cancellaria Coutliouyi, Jay, Cat. 1839. 

 Admete viridula, Stimpson, Check Lists, No. 6. 



Shell oblong, longitudinally obscurely ribbed, spirally lined, 



spire acuminated; Avhorls rounded, suture strong; aperture short, 



smooth, columella obsoletoly plaited; Avhite, under a pale green 



epidermis. Ten to forty fathoms. 



Massachusetts to Arctic Ocean. 



Genus TRICHOTKOPSIS, Brod. & Sowb. 



Zool. Journ., iv. 373. 1826. 



Shell thin, ventricose, keeled, umbilicated ; aperture longer than 



the spire, compressed into a partial canal in front ; epidermis 



horny, rising into hairs at the angles of the shell ; operculum 



horny, nucleus at one side. 



There are about a dozen species, principally of arctic distribu- 

 tion. 



1. T. BOREALis, Sowerb3^ Fig. 25. 



Zool. Journ., iv. 373, t. 9, f. G, 7. 183G. 

 T. costellatus, Coutliouy, Bost. Journ. Nat. Hist. ii. 108, t. 3, f. 3. 



Shell ovate-rhomboidal ; whorls four, the last very broad, and 

 encircled by four or five, and the others by two prominent, fringed 

 ribs, and crossed by minute and regular elevated lines. Fifteen 

 to twenty fathoms. 



From MassacJiusetis northioard, Northern British Coasts. 



