812 PROCEEDINGS OF THE NATIONAL MUSEVV. VOL.XX. 



end of the short rostrum which has a distinct, median, diagonal ridge or 

 angulation and another less distinct one at its base. The surface of the 

 shell is thickly covered with very numerous, and crowded, concentric, 

 more or less irregular, raised lines of growth which give it a finely lam- 

 ellose appearance when viewed under a lens. These lines become more 

 crowded, more prominent, and form two sinuous waves in crossing the 

 rostrum. Color, in alcohol, white tinged with reddish brown. The 

 hinge-margin is delicate; the right valve has no lateral tooth but 

 shows a slight thickening of the posterior margin; the cartilage-plate 

 is small, ovate, directed backward. 



Length, 6 mm.; height, 4.5 mm.; breadth, 3 mm. 



One live specimen (No. 52544), station 2570, N. lat. 39 54', W. long. 

 07 5' 30", in 1,813 fathoms, 1885. 



"Porcupine Expedition, 1870," off Cape Moudego, in 740 to 1,095 

 fathoms. Jeffreys. 



MYONERA LIMATULA Ball. 

 (Plate LXXIV, fig. 8.) 



Nea>,ra limatula DALL, Bull. Mus. Comp. Zoiil., IX, p. 112, 1881. SMITH, E. A., 

 Report Voy. Challenger, Zool. Lamellilmmchiata, XII, p. 35, 1885. 



Mi/onera limatula DALL, Bull. Mus. Comp. Zool., XII, p. 304, pi. in, fig. 5, 1886; 

 Bull. U. S. Nat. Mus., No. 37, p. 68, pi. in, fig. 5, 1889. 



A single live specimen (No. 38171) was taken at station 2048, N. lat. 

 40 2', W. long. 68 50' 30", in 547 fathoms, 1883. 



MYONERA (?) PRETIOSA, new species. 

 (Plate LXXVII, fig.5.) 



Shell small, very thin and fragile, nearly transparent, compressed, 

 elongate-oval with a well-defined, somewhat elongated rostrum. Umbo 

 prominent, scarcely oblique and nearly smooth. The antero-dorsal mar- 

 gin is convex, anterior end evenly rounded; ventral margin broadly 

 convex, becoming incurved at the base of the rostrum; postero-dorsal 

 margin nearly straight. The antero dorsal region is distinctly exca- 

 vated in front of the beaks. The body of the shell is ornamented with 

 ten or more thin, distinct, slightly raised, concentric riblets separated 

 by much wider interspaces. On the rostrum there are two well-marked 

 minutely spinulous keels between which are delicate lines of growth; 

 the first runs from the beak quite close to and parallel with the dorsal 

 margin ; while the second extends from the umbo diagonally across the 

 rostum to its lower edge. 



Length, 6 mm.; height, 3 mm.; breadth, about 2 mm. 



This shell has no very close resemblance to any hitherto described. 



One valve, station 2655, N. lat. 27 22', W. long. 78 7' 30", in 330 

 fathoms, among Foraminifera, 188G. 



As but a left valve was found, the true position of this species can 

 not be decided. 



