KONGL. SV. VET. AKADEMIENS HANDLINGAtt. BAND. 22. N:0 7. 



273 



the apex of the peduncle of the last pair; the peduncle is narrower than that in the first 

 pair, five times as long as broad, and considerably longer than the inner ramus, which 

 is nearly twice as long as the outer; the rami are serrated as in the first pair. The 

 peduncle of the third pair is shorter than the last coalesced ural segment, not fully three 

 times as long as broad, and only a little longer than the inner ramus, which is somewhat 

 longer than the outer; both rami are serrated as in the first pair. In some specimens 

 of this species I have observed peculiar features in the form of the uropoda, which 

 features I suppose to be connected with the moulting process, and which will be accounted 

 for in the morphological part of this treatise. 



The telson is obtusely triangular, and scarcely as long as broad; it is half as long 

 as, and much broader than, the peduncle of the last pair of uropoda. 



PARATHEMISTO RUBESCEtfS, J. D. Dana, 1852. 



Parathemisto 7'ubescens, J. D. Dana. 

 Facsimile from Dana. U. S. Expl. Exp. Crust. II, pi. 67, fig. 9. 



Fig. 1. The animal from the side. Fig. 2. The urus. 



Diagn. Corpus non carinatum. Caput segmentis quinque primis persei longius. Carpus pedum percci 



primi paris metacarpo longior(?). Carpus pedum quarti paris metacarpo multo brevior, 



ac duas spinas margini posteriori affixas gerens. Metacarpus pedum parium trium ulti- 



raorum articulis duobus praecedentibus brevior. Pedunculus pedum uri ultimi paris quam 



. telson ter longior; ramus externus parium trium omnium ramum internum longitudine aequans. 



The body is not carinated. The head is longer than the first five pergonal segments to- 

 gether. The carpus of the first pair of permopoda is longer than the metacarpus (?). The 

 carpus of the fourth pair is much shorter than the metacarpus, and has two bristles on 

 the hind margin. The metacarpus of the last three pairs is shorter than the two preced- 

 ing joints together. The peduncle of the last pair of uropoda is three times as long as 

 the telson; the outer ramus of all the three pairs is as long as the inner. 



K. Sv. Vet. Ak. Handl. Band. 22. N:o 7. OO 



