4 '2 BULLETIN GO; UNITED STATES NATIONAL MUSEUM. 



The carinal latus is triangular, with the umbo projecting he^^ond the 

 base of the carina and a little recurved. Several ribs radiate from 

 the umbo. 



The peduncle is about as long as the capitulum, closeh^ covered with 

 an open mosaic or pavement of very minute, scarcel}' imbricating 

 scales, of about 0.2 or 0.3 mm. width. 



Length of capitulum 20, width 12 mm. Length of peduncle 21 mm. 

 Length of the carina 10, diameter at l)ase 2 mm. 



In this species the inframedian lateral plate is of a peculiar irregular 

 shape. The rostral latera are narrow, unlike those of related species. 



A second example from the same station as the tvpe differs by hav- 

 ing the bordering ribs almost obliterated on the lower half of the 

 carina, and the inframedian lateral plate on the left side is almost 

 regularly quadrate (fig. lid). 



This species is named for Miss Mar}" J. Rathbun, the accomplished 

 carcinologist of the United States National Museum. (Fig. 11.) 



SCALPELLUM SOROR, new species. 



%?6.— Cat. No. 32913, U.S.N.M. 



Tyjpe-loGality . — Albatross Station 2818, Galapagos Islands, south 

 latitude 36' 30", west longitude 89^' 19', 634 fathoms, bottom tempera- 

 ture 39.9°. 



The capitulum is nearly twice as long as wide, the plates nearly in 

 contact, joined by narrow chitinous sutures, covered by a very thin 

 smooth cuticle. The ventral (occludent) border is straight. 



The scutum is narrow, the width contained 2i times in the length; 

 occludent and lateral margins are straight and parallel, the basal mar- 

 gin nearly at right angles with them. There is a very weak rib along 

 the occludent margin, and another from apex to the baso-lateral angle; 

 elsewhere the surface is marked with weak, widely spaced growth- 

 wrinkles only. 



The tergum is a trifle longer than the scutum, nearly three times as 

 long as wide. The occludent margin is straight, the baso-lateral 

 slightly convex, the carinal margin is slightly concave near the apex, 

 elsewhere slightly convex. It has weak sculpture of widely spaced 

 V-shaped growth-lines. 



The carina is well curved, with apical umbo. Roof deeply chan- 

 neled between two stout marginal ribs. Sides narrow. Basal margin 

 rounded. 



The upper lateral plate is quadrangular, the scutal and carinal ])orders 

 straight and parallel, the scutal more than double the length of the 

 carinal. The tergal margin is straight. Umbo acute and terminal. 

 The surface is marked with growth-lines only. 



There is a minute oval rostrum, deeply embedded in the cuticle and 

 readil}' overlooked. 



