360 "ENDEAVOUR" SCIENTIFIC RESULTS. 



beginning a little behind and above the angle 

 formed below the hepatic spine by the meeting of 

 the antennal sulcus with the ridge which terminates 

 in the antennal spine, and extending forward and 

 downward to an angle of about 30 to the longi- 

 tudinal axis of the carapace toward its antero-lateral 

 angle. 



semisulcatus, de Haan. 



b. Post-rostral carina not sulcate or grooved. 



i. Subhepatic crest formed by the lower margin of a 

 straight, longitudinal "incision" extending pos- 

 teriorly scarcely as far as the angle formed below 

 the hepatic spine by the meeting of the antennal 

 sulcus with the ridge which terminates anteriorly 

 in the antennal spine; rostrum with five to seven, 

 usually six teeth above, and most often three, 

 rarely four teeth below. 



esculentus, Haswell (p. 362). 



ii. Subhepatic crest longitudinal and arcuate; extend- 

 ing for some distance behind the angle formed 

 below the hepatic spine by the meeting of the 

 antennal sulcus with the ridge which terminates 

 anteriorly in the antennal spine; rostrum with 

 nine teeth above and two below. 



gracilirostris, Thallwitz. 



B. Carapace without a subhepatic crest. 



1. Rostrum exceeding the antennal scale by one-third to 

 two-fifths the length of its free portion. 



a. Last or anterior dorsal rostral tooth at most placed 

 over the last or terminal segment of the antennular 

 peduncle, often not so far forward. 



indicus var. longirostris, de Man 



(adult and juvenile). 



b. Last, or anterior dorsal rostral tooth invariably 

 placed in advance of the last, or terminal segment 

 of the antennular peduncle. 



merguiensis, de Man (juvenile). 



2. Rostrum about as long as antennal scale, rarely and 

 then only slightly exceeding it; often shorter than 

 the antennal scale. 



a. Dactyl of third or external maxillipeds of adult 

 male about as long as or markedly shorter than 

 propodus. 



i. Dactyl of third maxilliped of adult male about as 

 long as propodus. Rostral crest, in both sexes, 

 only of moderate height. 



indicus, M. Edw. 



ii. Dactyl of third maxilliped of adult male, scarcely 

 half as long as propodus. Rostral crest proximally 

 conspicuously high and of broad triangular form 

 in both sexes. 



merguiensis. de Man (adult). 



