CRUSTACEA. 259 



at tlie time in tlie Annales des Sciences naturelles is a female, answering altogether to tlie specific 

 features in the specimens of the same sex now hefore ns. 



There can be also no doubt as to the specific identity of both d'Orbigny's and Gay's figures, 

 the originals of which were procured at Valparaiso. Tiiay both represent the female. 



Specimens of both sexes were brought home by Lieutenant G-illiss. In the female the 

 external maxillipes are equal in length to the distance between the apex of the rostrum and 

 the articulation of the caudal region upon the thorax. The first pair of legs extends to nearly 

 the serrated portion of the rostrum ; the apex of their chela, therefore,' does not reach as far as 

 the extremity of the latter organ. The tip of the second pair of legs is even with that of the 

 first pair, though inserted behind it. The third pair of legs is the longest, projecting beyond 

 the second and first pairs, and extending to nearly the apex of the rostrum. The tip of the 

 fourth pair is nearly even with the second and the first. Finally, the extremity of the fifth 

 pair reaches the base of tlie last article of the third j^air; its tip, therefore, remaining behind 

 that of all the others. The rostrum is equal in length to the middle line of the cephalo-tho- 

 racic region. Now there can be no doubt as to the identity of these specimens with those 

 figured by d'Orbigny and Gay. 



In the male the external maxillipes are nearly as long as the absolute length of the animal , 

 since they equal the distance between the apex of the rostrum and the middle of the length of 

 the caudal paddles. The first pair of legs is stouter, the hand more elongated, and extending 

 beyond the apex of the rostrum for the whole length of the finger. The second pair is very 

 slender, hardly reaching with its extremity the middle of the hand, and not quite as far as the 

 denticulated portion of the upjDer edge of the rostrum. The third pair extends to the base of 

 the moveable finger or upper joortion of the big claw, and consequently a little beyond the apex 

 of the rostrum. The tip of the fourth pair is nearly even with, mayhap slightly longer than 

 the second. Finally, the fifth pair slightly projects bej^ond the base of the last article of the 

 third pair. The rostrum is somewhat longer than the middle line of the cephalo-thoracic 

 region. The antennas are longer than in the preceding instance. In every other particular 

 both sets of specimens appear to agree perfectly. Those from which our description is drawn 

 belong to the latter group. 



■ KHYNCHOCINETES TYPUS, Edw. 



Spec. char. Dull greenish, variegated with yellowish red. Locomotory appendages and jaws 

 transversally barred or annulated with pinkish. Patches of the latter hue are also observed 

 upon the convexity of the caudal region. 



Syn. Rhynchocinetes typus, Edw. Ann. Sc. Nat. 2de Serie VII, Zool. 1837, 165, PI. iv, 0. — 

 Hist. Nat. Crust. II, 1837, 383. 

 Edw. et Lucas, in D'Orh. Voy. Amer. Merid. VI, i; Crust. 1843, 36, PI. xvii, 



fig. 1. 

 Nic. in Gay, Hist, de Chile, Zool. Ill, 1849, 216; Crust. Lara, i, fig. 7. 

 Rhynchocmetes typicus, Dana, U. .S. Expl. Exped. Crust. XIII, I, 1852, 568, PI. xxxvi, 

 fig. 7. 



Descr. The following description is based upon the male : The entire length, from the tip of 

 the rostrum to the extremity of the caudal paddles, is four inches and a quarter ; the rostrum 

 measures one inch and an eighth ; the middle line of the cephalothorax one inch and a six- 

 teenth . 



The cephalothoracic region is rounded above, compressed, deeper than broad, smooth, with 

 the excej^tion of the anterior extremity, which is jirovided with eight acerated points ; two of 

 which being situated upon the middle line, and one immediately above tlie base of the rostrum : 



