Mr. C. Spence Bate on new Species of Crustaceans. 489 



side to side, slightly posterior to the points of the broadest diameter 

 in the carapace. The pleon is triangular, and smaller and narrower 

 than in the female, having the lateral margins more straight and 

 symmetrical. 



The only male specimen in the collection is smaller than the female, 

 and the surface generally more tuberculated. The right propodos of the 

 first pair of pereiopoda is larger than the left, and is so well deve- 

 loped as scarcely to be capable of being folded within the limits of 

 the carapace. The length of the male animal, from the extremity of 

 the rostrum to the centre of the posterior margin of the carapace, is 

 about |ths of an inch ; its breadth, from the point of one lateral ex- 

 tremity to the other, is about 1| inch. 



The size of the largest female in the collection is in length about 

 I5 inch, and breadth about 2 inches. 



Cryptolithodes alta-fissura, n. s. 



Female. 



This species may readily be distinguished from the two previously 

 known by the smoothness of the carapace, propodi, and pleon, and 

 more decidedly by the deep orbital notch on each side of the rostrum. 



The carapace is nearly as broad again as long, and produced con- 

 siderably posteriorly to the cardiac elevation — a feature that appears 

 to belong to the female. The rostrum is broad, flat, and rectangular. 

 The antero-lateral margins are produced so far anteriorly as to be 

 nearly in a line with the extremity of the rostrum ; a deep notch, in 

 which the eyes are situated, exists on each side of the rostrum. The 

 anterior margin is slightly marked with distant small points. The 

 posterior margin is quite smooth and even. The dorsal surface is 

 quite smooth, and pencilled in light red upon a yellowish ground, the 

 red pencilling being fine and delicate, following the contour of the 

 margin and surface of the carapace. 



The pleon is subsymmetrical and very smooth, and planted con- 

 siderably within the posterior margin of the carapace. The second 

 segment (first visible) has the marginal plates fused with the central. 

 The sixth segment is without lateral plates ; and the telson is si- 

 tuated beneath, and anterior to, the posterior extremity of the sixth 

 segment. 



The eyes are small, and placed upon peduncles that gradually taper 

 from the base to the extremity. The first pair of antennae are short, 

 and developed upon the type of those of the Brachyura ; but the first 

 joint is reduced to a size that is only about twice the diameter of the 

 second. The second pair of antennae are but little longer than the 

 first, and are furnished with a broad round scale at the third joint, 

 and a terminal flagellum that is about the length of the fifth joint of 

 the peduncle. The squamiform appendage is circular and disk-like ; 

 the inner margin is straight or somewhat excavated. 



The second pair of gnathopoda have the third joint much broader 

 than the fourth (the secondary appendage reaches not to the extre- 

 mity of the third), and have the terminal joints small and rudimentary. 

 The first pair of pereiopoda are subequal in the female, the propodos 



