REPORT ON THE CRUSTACEA MACRURA. 



861 



Length, entire, 



,, of carapace, 



„ of rostrum, 



„ of pleoo, . 



„ of third somite of pleon, 



,, of sixth somite of pleon, 



,, of telson, . 



Habitat. — Station 233a, May 19, 1875 ; 

 depth, 50 fathoms ; bottom, sand. Two spec 



18 mm. (0-7 in.). 



6 „ 



3 „ 



12 „ 



3 „ 



4 „ 

 4 „ 



lat. 34° 38' N., long. 135° 1' K; off Japan ; 

 mens ; one male. Dredged. 



The carapace is smooth, slightly carinated on the anterior portion, and produced to a 

 pointed rostrum, which is depressed anteriorly. The dorsal surface is smooth. The 

 pleon is slightly carinated to the posterior extremity of the fifth somite, which is produced 

 to a sharp point in the median line. The sixth somite is considerably narrower, and is 

 armed with a small tooth on the dorsal surface near the anterior extremity, and with a 

 small and slender spinedike tooth near the posterior extremity of the infradateral margin. 



The telson is long, slender, tapering, armed laterally with three strong, solitary, 

 equidistant spines, and terminating in two long spines ; the dorsal surface is channelled 

 in the median line. 



The ophthalmopoda are more slender than in the previous species ; the ophthalmus is 

 orbicular. 



The first pair of antennae has the peduncle longer than the rostrum, and has the first 

 joint excavate to receive the eye ; the flagella are unequal, one being nearly half the 

 length of the animal, and the other scarcely half the length of the carapace. 



The second pair of antennae has the scaphocerite longer than the peduncle of the 

 first pair, and carries a flagellum that is broken off in our three specimens, but which 

 Stimpson says is scarcely longer than that of the first pair. 



The pereiopoda correspond closely with those of Leptochela serratorbita. 



Observations. — This species, the specimens of which were procured off the southern 

 coast of Japan, corresponds with the description of those taken by Stimpson in the Gulf 

 of Kao-osima. The only points that do not correspond with it are the presence of a small 

 tooth or tubercle on the anterior portion of the sixth somite of the pleon, and the small 

 slender tooth on the infradateral margin near the posterior extremity. In the female 

 the form of these is frequently reduced to a small point. 



It may be that Stimpson's description was taken from a female, but if so, the specific 

 name does not correspond, and it is less slender and graceful than the male. In the 

 female the anterior somites of the pleon have the lateral or coxal walls deeper than in 

 the male. 



The ova are oval, very numerous and small, being less than 05 mm. in diameter. 



Stimpson's specimens were taken at a depth of more than 40 fathoms. 



