836 THE VOYAGE OF H.M.S. CHALLENGEE. 



sharp tooth-like point, whence the lower margin recedes obliquely in an outwardly curved 

 line to the orbit. 



The pleon is not carinated, and the third somite is posteriorly produced to a point or 

 depressed tooth in the median line ; the other somites are smooth. 



The ophthalmopoda are short and robust, having a short thick tubercle on the inner 

 surface, distinct from the ophthalmus, which is black in colour and larger in diameter 

 than the stalk. 



The first pair of antennae has the peduncle short and the first joint deeply excavate ; 

 the outer flagellum is very large and the inner slender. 



The second pair of antennae has a scaphocerite that is longer than the peduncle of the 

 first pair. 



The first pair of gnathopoda is subpediform and has the terminal joints reflexed. 



The second pair of gnathopoda is pediform and reaches beyond the distal extremity of 

 the scaphocerite. 



The first pair of pereiopoda is chelate, the meros being long, broad, and transversely 

 compressed ; the second pair is longer than the first and also has the meros long and 

 laterally compressed. The three following pairs are not much longer than the second ; 

 the third and fourth have the meros long, broad, and of great tenuity. 



The first pair of pleopoda has the inner branch reduced to a rudimentary subfoliaceous 

 petasma ; all the others have the rami subequal, those of the posterior pair helping to 

 form the rhipidura. 



The telson is longer than the inner branch of the sixth pair and subequal with the 

 outer ; the dorso-lateral angle is fringed with a series of minute spinules. 



Tropiocaris tenuipes, n. sp. (PI. CXXXVI. fig. 2). 



Eostrum anteriorly produced to a level with the distal extremity of the first joint of 

 the first pair of antennae, dorsal surface armed with four or five distantly placed minute 

 denticles ; first antennal tooth reduced to a minimum, second antennal tooth small. 



Pleon carinated from the third to the sixth somites ; third somite posteriorly produced 

 to a dorsal tooth ; the three following terminating abruptly or with a minute pro- 

 jection. 



The appendages of the only specimen are very much damaged. 



Length, entire, . 



of carapace, 



of pleon, 



of third somite of pleon, 



of sixth somite of pleon, 



of telson, 

 Diameter of meros of fifth pereiopod, 



