710 - MR. w. T. CALMAJf OjS' machurous [May 16, 



is equal in length to the merus, somewhat expanded distallj, where 

 the breadth is about one-fifth of the length. The hand is rather 

 wider than the distal end of the carpus, not perceptibly compressed 

 (the two diameters are about as 5 : 6), a little less than twice the 

 length of the carpus Palm shorter than the carpus, and rather 

 shorter than the fingers, dingers straight, meeting along their 

 whole length; inner margins with smooth cutting-edges, without 

 any trace of teeth save a single very minute tubercle near the 

 base of the dactylus. The surface of the whole limb bears widely- 

 scattered very minute setfe ; on the distal part of the carpus and on 

 the inner .side of the palm are a number of small spinules. The 

 succeeding pairs of perseopods are long and slender, the fourth 

 pair extending beyond the antennal scale. The dactylus is nearly 

 one-third the length of the propodus. 



End of telson (PL XL. fig. 24) with a sharp median point, 

 longer than the outer but shorter than the inner pair of 

 terminal spines. 



Seven specimens, most of them very imperfect, are in the collec- 

 tion; only one of the large chelae is preserved. One specimen is a 

 female carrying ova. The species was dredged at a depth of 

 50 feet. 



Length of largest specimen (S), 25 mm. 



Length of ovigerous female, 23 mm. 



Length of specimen figured (S), 18 mm. 



Length of 2nd perseopod of same, 11-5 mm. 



The very large number of closely-allied species included in the 

 genus Palcemon, and the very great differences (as yet only partly 

 elucidated) which may exist between individuals of the same 

 species of different ages and sexes, render it somewhat hazardous 

 to attempt to define a new species from such scanty material. 

 The presence of an ovigerous female in the collection shows that 

 the species is one of the smallest, if not the very smallest species 

 of the genus. On the other hand, we cannot be quite certain 

 that the single male specimen upon which our description is 

 mainly based has attained its full development in the characters 

 of the chela \ 



Assuming, however, for the present that this is the case, the 

 species will fall into the group Eupcdcemon as defined by Ortmann 

 (Zool. Jahrb., Abth. f, Syst. v. 1891, p. 696), in which the second 

 perseopods are cylindrical, while the equality of the merus and 

 carpus of these appendages and the characters of the telson will 

 bring it into proximity with such species as P. scabriculiis Heller 

 and P. endthensis de Man. P. niloticus Eoux, the only species known 

 from North Africa, is somewhat similar to the present form, but, 

 so far as can be judged from the more or less defective figures 

 and descriptions of Eoux (Ann. Sc. JSTat. xxviii. 1833, p. 73, 



^ Since this paper was read I have received several additional and better 

 preserved specimens of both sexes from Mr. Moore's collections. They agree 

 in all essential points with the description given abore. 



