SOLARIELLA. 311 



prominent spiral ribs, 4 on the last, 2 or 3 on the penultimate whorl, 

 clathrate with elevated, distant longitudinal lines ; bat-e sculptured 

 with about 10 im])ressed spiral lines, decussated by arcuate lines. 



Alt. 6\, diam. 7 mill. 



Norwegian coast; Off Cajie Cod, Mass.; Off Cape Sal/e, Nova 

 Scotia in 90 fms., etc. 



Margarita bella Verkruzen, Jahrb. d. ]Mal. Gesellsch. 187-"), p. 

 236 (no description).— il/ac/iccro79Z«:c hella Verkr. Sars, Moll. Reg. 

 Arct. Norv., p. 137, t. 9, f. 4. — Machceroplax obscura var. bella Verkr. 

 Verrill, Trans. Conn. Acad. Sci. v, p. 531 (1882).— i)/. bella Verkr. 

 Verrill, Proc. U. S. Nat. Mus. 1880, p. 378. 



I have no doubt of the intergradation of the forms bella, obsev.ra 

 and Imvis. These three form a series varying from highly-sculptured 

 to smooth. Verrill's observations on M. bella as dredged by him off 

 the New England coast are as follows : It differs from the typical 

 obscura chiefly in having the base covered with distinct incised 

 spiral lines. In some specimens the curved radiating ribs or un- 

 dulations on the base are well marked, as in the typical form, in 

 others they are more or less obsolete. The presence of a slight spiral 

 carina, or angle, bordering the umbilicus, is variable in both forms, 

 being in some specimens, pretty well developed, in others entirely 

 absent. The sculpture on the upper whorls is also variable in both 

 varieties. The transverse ribs are usually more evident in var. 

 bella, but they ai'e often equally evident in typical obscura. 



S. VARicosA Mighels and Adams. PI. 66, figs. 16, 17. 



Shell small, thin, low, conical, of a dingy white or drab color; 

 whorls 4, convex, covered with numerous longitudinal oblique ribs ; 

 intersected by a great number of revolving strife, which are most 

 conspicuous on the lower part and base of the lower whorl. The 

 striae on the upper part of the whorls can only be seen with a 

 magnifier. Suture distinct, subcanaliculate ; umbilicus rather large 

 and deep, bounded by two rather rugged varices, intersected by the 

 ribs which are continued to the verge of the umbilicus. Aperture 

 circular; labrum simple, sharp; within pearlaceous. 



Alt. 6i, diam. 6] mill. (Migh. and Ad.) 



Newfoundland Northward ; Norway; Nova Zembla. 



Margarita varicosa M. and A., Bost. Journ. Nat. Hist, iv, p. 46, t. 

 4, f. 14 (1842). — Gould, Binney's edit., p. 285, f. 547. — 3fachceroplax 

 varicosa jMigh. Sars, ■:Mo11. Reg. Arct. Norv., p. 139, t. 9, f. 2.— if. 



