ball: mollusca and brachiopoda. 393 



Sacco proposes to retain D'Orbigny's name Pectunculina for those species 

 ■with stronger sculpture and denticulate valve margins, ■while for those intermediate 

 between these and the smooth-edged type of L. aurita, Rovereto has proposed the 

 name Cosmetopsis. These mutations of sculpture are too feeble, and in one case 

 too characteristic of different ages in the same individual, in my opinion, to be 

 worthy of names. 



Felicia is apparently founded on a misconception. A large number of specimens 

 were dredged by the " Albatross," aud the series sho^ws the impression of the tri- 

 angular fossette to vary exceedingly in strength and when slightly eroded to be 

 in some cases very easy to overlook. Its supposed absence, in Felicia as claimed, 

 is thus easily accounted for. 



There is, however, one good subdivision of the genus, as follows : 



EMPLECOXIA Ball, sect. nov. 



Valves ■with their upper posterior margins beyond the hinge line, deeply in- 

 folded, forming a deep narro^w pit between the valves when closed. 



Type, Limopsis vaginatus Call, Proc. U. S. Kat. Mus., 1891, 14, p. 190 ; 1S95, 

 17, p. 713, plate 25, figures 3, 6, 7- Beriug Sea and North Pacific Oceau. 



LIMOPSIS s. s. 

 (A. With entire margins.) 



Limopsis zonalis Dall, n. sp. 



Plate 7, figures 6, 9. 



Shell large for the genus, compressed, obhque, ovate, ■whitish, clothed with a 

 dense elongate villous periostracum of a dark brown color with narrow concentric 

 zones which are nearly black ; beaks narrow, sharp, prominent, vertically in- 

 curved over a short lozeuge-shaped ligament centrally situated in a rather short, 

 narrow, flat amphidetic area; beaks nearly smooth, the greater part of the disk 

 covered with small, low, slightly irregular, closely adjacent ridges, bearing fringes 

 of periostracum, crossed by very faint radial incised lines, ■with rather wide inter- 

 spaces, from which, over the lines project long hair-like processes in thick rows, 

 extending beyond the margins of the shell ; interior polished white with broad, 

 flat, entire margin; hinge hne with eight anterior and five or six posterior, 

 radially arranged smooth teeth, the two series separated by a short gap ; anterior 

 adductor scar small, deep, adjacent to the hinge plate ; posterior scar four or five 

 times as large aud distant from the hinge plate. Alt. 25 ; lat. of shell, 27 ; of 

 hinge area, 11.5 ; max. diam. 10 mm. 



U. S. S. "Albatross," station 3356, Gulf of Panama, in 5i6 fathoms, mud, bot- 

 tom temperature 40°. 1 F. U. S. N. Mus. 122, S7S (type). Other specimens wore 

 obtained from stations 3357 aud 335S, in 782 aud 555 fathoms, green sand. 



