PEOCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 333 



AcUs toiiiis Verrill. 



Trans. Conn. Acad., v, p. 528, pi. 58, fig. 19, July, 1882. 

 Eulimdla ventricosa (pars) Vernll, these Proc.,iii, p. 380,1880 (won Forbessp.) 



Shell very slender, smooth, white, acute. Whorls nine, evenly 

 rounded; surface with few, faint, microscopic, rai,«ed, spiral lines; suture 

 impressed; aperture elliptical, a little effuse in front. Nucleus small, 

 regularly spiral, not upturned. Length, 3.8""'^; breadth, l'""". 



Station 873, in 100 fathoms, 1880. 



EHIPHIDOGLOSSA. 



Machaeroplax obscura, var. bella (Verk.). 



Macha;ro2ilax hella Friele; Verrill, Proc. Nat. Mus., iii, p. 378, 1880. 



Station 1032, off Martha's Vineyard, 208 fathoms. 



Doubtless this is only a strongly sculptured variety of M. ohsaira. 



Machwroplax cinerea (Couth.) Friele. 



Margarita cinerea Gould, Invert. Mass., ed. ii, p. 279, fig. 539. 



This species, which had not occurred south of Cai)e Cod previously, 

 was taken at station 981, in 41 fathoms, off Chatham, Cape Cod. 



Cydosircma Dalli Verrill. 



Trans. Conn. Acad., v, p. 532, pi. 57, fig. 39, July, 1882. 

 Cijdostrema trodioides Verrill, these Proc., iii, p. 378, 1880 (non Jeffr., Sars). 



This shell differs from C. trodioides in having the base covered around 

 the umbilical region with six to eight very distinct, incised, spiral lines. 

 The umbilicus is closed, or represented only by a slight and narrow pit. 

 The surface of the shell has only a little luster, and is slightly rough- 

 ened by very faint and close lines of growth. 



Color, yellowish white. Height, 2""" ; breadth, 2.25"''^\ 



Station 892, in 487 tiithoms. 



Cyclostrema rugulosum (Jeffreys, MSS.) Sars. 



G. O. Sars, Moll. Reg. Arct. Norvegite, p. 129, pi. 21, figs. 1, a, h. 



Station 894, in 365 fathoms, 1880. 

 Northern Norway, 80-200 fathoms, — Sars. 



Fissurella Tanneri Verrill, sp. nov. 



Shell large, ovate, rather thin, with regularly and finely decussated 

 sculpture. Apex nearer the anterior (smaller) end, moderately elevated. 

 Perforation not large, round-ovate, conformable with the outline of the 

 shell, but more rounded. Whole surface covered with rather fine, raised, 

 radiating lines, with interstices of similar width or narrower; these are 

 decussated by numerous concentric raised lines, which rise into nodules, 

 or, towards the margin, form small, arched lamella? in crossing the radii. 

 Shell, externally, pale yellowish gray, internally lustrous bluish white ; 

 edge finely creuulated. Length, 40"'™; breadth, 31'"'^; height, IG™'"; 

 longest diameter of apical foramen, 4""" ; its breadth, 3™"'. 



Off Delaware Bay, station 1040, in 104 fathoms,— Lieut. Z. L. Tanner, 

 1881; one living specimen. 



