524 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



This species has been compared with the Belas in the chief museums: 

 and private collections of Northern Europe, and seems amply distinct 

 from any of the species contained in them. 



Bela murdochiana u. s. Plate ii, fig. 8. 



Shell -whitish, short, stout, with rather coarse sculpture and verv 

 short spire, whorls about five, the last much the largest ; whorls in- 

 tiated, suture deep, almost channeled, sculpture of numerous (on the last 

 whorl about two to the millimeter) narrow, backwardly convex, tlexu- 

 ous riblets with about equal interspaces, strongest near the suture, not 

 crossing the fasciole and obsolete near the periphery ; lines of growth 

 distinct, crossed by numerous (about six to the millimetei) rather 

 coarse threads, of which each alternate one tends to be smallei-, s(>pa- 

 rated by narrow grooves and about uniformly distributed over the sur- 

 face, with a tendency to a faint carina in front of the indistinct fasciole* : 

 outer lip sharp, columella simple, white ; aperture pinkish, canal short» 

 wide; nuclear whorls eroded in the specimens; operculum light horn 

 color, rather broad and short ; soft parts pink. Longitude of shell, 

 11.5; of last whorl, 10.0; maximum latitude of shell, 8.5""". Museum 

 No. 40960. • 



Specimens were obtained from Cape Smythe in 2 to 5 fathoms mud 

 and sand with young B. tenmliraUt, from which they differ in lighter 

 color of shell, coarser sculpture, and stouter proportions. The opercu- 

 lum of B. tenuUirata is black, narrow, and claw-shaped. 



The species is dedicated to Mr. John Murdoch, naturalist to the 

 Point Barrow party. 



Admete Middendorffiana Dall. 



Admete viridula, M\dd. Mai. Ross, ii, i>late ix, figs. 13,14, 1849, not of Fa- 

 Lricius. 



This form is perfectly distinct from A. viridula, and may prove to be 

 a Cancellaria. It is one of the characteristic forms of the Pacific arctic 

 and ranges north from Nunivak Island. The present specimen was 

 obtained in 5 fathoms mud, in Norton Sound. Museum No. 409G1. 



Cturysodomus Kroyeri Moller var. Rayana Dall. 



A specimen of C. Kroyeri, in the state called cretaceus by Keeve, was 

 found on the beach at Cape Smy the ; a very large living specimen of the 



* It now being certain that the notch in the Pleuroiomidir is for the purpose of 

 allowing the etfete matters to escape froui the anus without fouling the water going 

 to the gills, the term anal fasciole is here propo.se«l for the band marking the track of 

 the notch which in Pleurotoma and its allies, in Pleiirotomaria, Seinnurella, Rimula 

 smd its relatives, &c., forms a conspicuous feature in the sculpture, for which, hith- 

 erto, there has been no convenient term for use in description. The siphonal fasciole, 

 named by Prof. Theodore Gill, bears a somewhat similar relation to the anterior end 

 of the canal, bnt is generally less distinctly marked off from the rest of the surface. 

 For the notch itself the term atial notch may be used, to distinguish it from the sipho- 

 nul notch, in description. 



