44 



Post-rostral carina low, broad and faint ; nearly reaching the posterior border 

 of the carapace. An orbital spine. A strong post-antennular (antennal) spine, 

 the buttress of which reaches the hepatic fossa. A fine suture runs along the 

 anterior part of the floor of the shallow post-antennular sulcus, A similar 

 transverse suture is seen on the branchiostegite, at the level of the 3rd pair of 

 chelipeds. Hepatic spine rather small. Antero-inferior angles of carapace dis- 

 tinctly dentiform. A very indistinct subhepatic groove (the anterior part of 

 the cervical groove) runs from the base of the post-antennular buttress to the 

 base of the hepatic spine : dorsal of the hepatic spine the groove cannot be dis- 

 tinguished. 



On the 2nd abdominal tergum there is a median compressed tubercle. 

 The 8rd — 6th terga are very sharply carinated. The 5th abdominal somite is 

 about two-thirds the length of the 6th, the 6th is about as long as the telson. 

 The telson, which is dorsally grooved, is much shorter than the inner caudal 

 swimmeret, ends rather abruptly, and has, on either side, a very obscure subter- 

 minal marginal spinelet as well as two hardly perceptible lateral spinules. 



The antennular flagella of the male are about three-fourths, those of the 

 female about two-thirds, the length of their pedimcle : the lower fiagellum is 

 much the coarser. The 3rd maxillipeds are coarse, except the dactylus, and 

 reach into the anterior third of the antennal scale. The last pair of thoracic 

 legs reach at least a dactylus-length beyond the tip of the antennal scale. A 

 basal spine is present on the first two pairs of chelipeds. All the thoracic legs 

 have petaloid exopodites. 



The andricum is anchor-shaped. 



The thelycum consists of a transverse bar between the 5th pair of legs and 

 a concave semilunar plate between the 4th. 



The female reaches a length of 3f inches. The colours in life are pink, the 

 abdominal carinae and thoracic appendages being milk white. 



It differs from T. curvirostris Stimpson ( = T. ancJioralis Spence Bate), of 

 which we have both "Challenger" specimens from Japan and other specimens 

 from Hongkong, in the following particulars : — 



The rostrum is quite straight and has more teeth, and the post-rostral 

 carina is much fainter. 



The antero-inferior angles of the carapace are sharper, and the anterior 

 part of the cervical groove is much less distinct. 



The antennules are shorter, both in their peduncle and in their flagella ; 

 and the 5th pair of legs are longer. 



Though the andricum and thelycum are much alike, specimens of the same 

 size being compared, yet they differ a good deal in detail. 



