iSOPODS OF NORTH AMERICA, 



247 



(^([ual width. The terminal seo-nu'iit is i-ouiided ])()steri()rly or slig-htlj' 

 triang-ular. The uropoda are very shoit. less than lialf tlie h'lioth of 

 tiie terminal seniiuMit; the l)raiu'hes are e(|iial in length. 



Fk;. 257.— Indusa carixata. a, Second maxilla. 

 X 39. b, First maxilla, x 39. c, Maxiujped. 

 X 20i. 



Fui. 258. — Indusa 

 carinata. Leg 

 ofseventh pair. 

 X 7. 



There is a hioh carina on tiie four posterior })airs of leg-s, and a 

 small one on the three antt^rior pairs. Color reddish ])rown. 



Two specimens, a male and a female, were collected by Prof. C. H. 

 (lilbert from the west coast of Panama. They were found in the 

 mouth of Mugtl Iio/<j>(St. 



Type.—QiiX. No. L^SlMIl, IT.S.N.M. 



41. Genus CYMOTHOA Fabricius. 



Body ovate. Head more or less deeply inuiiersed. 



First pair of antenna? widelj' separated at the base, rather com- 

 pressed. First thoracic segment manifestly longer than the second; its 

 anterior margin more or less sinuated, with the anterior angles short 

 or produced. P^pimera distinct on all the segments with the excep- 

 tion of the first; those of the first five pairs do not reach b\^ a greater 

 or less distance the posterior angle of the segment; the posterior ones 

 reach the posterior angles of the segment or extend beyond by a small 

 distance. 



The alidomen is deeply immersed, manifestly separated from the 

 thorax, and abruptly narrower than the thorax. The legs are rather 

 short, those of the first three pairs being a little shorter than the others. 

 Carina of the four posterior pairs of legs high. 



ANALYTICAL KEY TO THE SPECIES OF THE GENUS CYMoTIIOA. 



II. .Vutero-lateral angles of the first thoracic segment extend lialf tlie lengtli of the 

 head or less. Eyes distinct or only traces of eyes apparent. First segment of 

 thorax one and a half times longer than second segment, l^ropoda short, shorter 

 than the terminal at)d()minal segment. 

 h. Antero-lateral angles of the first thoracic segment narrow. 



('. Antero-lateral angles of the first thoracic segment acntely produced and reach- 

 ing the middle of head Ciimotlioa exrisa Pertv 



