REPORT ON THE CRUSTACEA MACRURA. 819 



its present condition is about twice the length of the animal, and is broken off at a point 

 where it is still thick. 



The second pair of gnathopoda reaches to a level with the apex of the rostrum. 



All the pereiopoda are broken off, but one or two unattached limbs that appear to 

 belong to this species are preserved. They are long, the carpos, probably of the fourth 

 pair, being specially so, very nearly equalling the combined lengths of the meros and 

 ischium ; the ischium is slender, cylindrical, 22 mm. long, and armed near the meral 

 joint with t\?o long teeth, one on the upper, the other on the lower and inner surface ; 

 the meros is 48 mm. in length, and armed on the upper surface with a row of distant 

 teeth, of which the most anterior stands close to the carpal joint, and a second row of 

 rather smaller teeth, in position intermediate with the others, on the lower; the carpos is 

 63 mm. in length and 0"2 mm. in diameter, or 7 mm. shorter than the meros and ischium 

 together, it is cylindrical and smooth from the meral to the propodal joint, at which it 

 increases in diameter from one-fourth to one-half of a millimetre ; the propodos is 2 mm. 

 long, and increases in diameter from the carpal to the dactylar joint, where it terminates 

 in an oblique margin that is about 0'5 mm. in length ; the dactylos is 3 mm. in length 

 and waved as in Nematocarcinus undidatipes. 



There is also a detached cheliped which I believe to belong to the second pair of 

 pereiopoda of one of the specimens of this species. The several joints have the following 

 dimensions: — carpos, 40 mm.; meros, 28 mm.; ischium, 19 mm.; chela, 4 mm. and 

 0"8 mm. broad ; digits, 1*5 mm. The meros is armed with small teeth and the carpos is 

 smooth. 



The penultimate pair of pereiopoda may therefore be considered to be rather more 

 than twice the lenoth of the animal. 



The third somite of the pleon does not project much over the fourth, and the 

 posterior somites are not much compressed. 



The telson is equal in length to the sixth somite, as well as to the outer rami of the 

 rhipidura. 



Nematocarcinus serratus, n. sp. (PL CXXXII. fig. 11). 



Eostrum more than half the length of the carapace, slightly elevated from the base 

 to the apex, and furnished with thirty-two teeth or spinules on the upper surface and 

 with none on the lower. 



Ophthalmopoda rather small. 



First pair of antennae having the peduncle one-third shorter than the rostrum. 



Second pair of antennas having the scaphocerite subequal to or scarcely longer than 

 the rostrum. 



Telson wanting. 



