294 DE. J. G. DE MAN ON SPECIES OF PAL^MON 



as hi^h as that below it. Three teeth are on the cephalothorax, the fourth is situated 

 just before the orbital margin. 



Von Martens describes the rostrum as being as long as the scaphocerites {I. c. p. 34), 

 but in his figure it does not reach so far ; this figure, however, is inaccurately drawn, for 

 the lateral spines of the cephalothorax have been forgotten altogether. 



The hepatic spine is a little smaller than the antennal, and is situated posterior to and 

 somewhat below the latter. 



The cephalothorax is covered, though not closely, with very small spiimles, which are 

 only 0-04 mm. long. The abdomen is finely punctate. The first segment (PI. 18. fig. 3) 

 presents a remarkable form, which has not hitherto been observed in any species of 

 this genus, the dorsal part of it being distinctly tricarinate by three, not very sharp, 

 longitudinal carina, that reach from the antetnor to the posterior margin of the segment. 

 The two lateral carinse converge very slightly backwards, and the upper surface is concave 

 between the median crest and each lateral one ; even on the outer side of each lateral 

 carina the surface appears a little concave, though a second lateral crest does not exist. 

 Though the second segment is not at all carinate, its surface appears, however, on each 

 side of the median line, near the posterior margin, very slightly concave. The third and 

 fourth segments are rounded above, but the fifth is distinctly carinate in the median 

 line of the dorsal surface, though only along the posterior half ; on each side of the crest 

 the surface appears a little concave. The telson tapers rather strongly towards the 

 posterior extremity (fig. 4), tliat ends in a sharp acute median tooth, which is shorter than 

 the internal of the two sj)ines on each side of it. The uj)per surface of the telson is 

 roughened by minute spinules, which are still smaller than those of the cephalothorax. 

 The anterior pair of spines on the upper surface is a little farther from the anterior end 

 of the telson than from the posterior extremity ; it is, of course, very seldom that a 

 third spine occurs on the left side, close to the anterior one. 



The short filament of the upper antennse is united for a very short distance with the 

 outer one, this distance being only one-third of the length of the third joint of the 

 peduncle. The external footjaws project half their terminal joint beyond the peduncles 

 of the outer antennae. The legs of the first pair overreach the scaphocerites by the 

 length of their hands : the fingers are just as long as the palm. The carpus, which is 

 somewhat thickened as usual at its distal end, is 5 -5 mm. long, the hands are 3'6 mm. 

 long; so that the caipus is only once and a half as long as the hand (fig. 5). 



The legs of the second pair (fig. 6) are equal and rather feeble; they project a 

 foiu'th of their wrist beyond the scaphocerites. Measured along its upper margin, 

 the merus appears 52 mm. long ; this joint is almost cylindrical and thickens but very 

 slightly anteriorly, so that it is 1'6 mm. thick at the distal end. The carpus, which 

 is 6'4 mm. long, is distinctly somewhat longer than the merus : von Martens says that 

 both joints are equally long, but in his figure the merus appeal's distinctly shorter. 

 The carpus also thickens gradually towards the distal end, and is, moreover, slightly 

 compressed ; in consequence of this, the distal extremity appears 1'9 mm. broad looked 

 at from above, but only 1'65 mm. when it is measured at the outer side (fig. 7). 



