2 I I 



As to the abdomen, it has been repeatedly stated in the present paper, that both in Ceratoplax 

 and in Typhlocarcinus the first segment in both sexes shows a tendency to extend laterally; 

 this has only been accomplished more fully in Typhlocarcinops and occurs also in my specimens 

 of Typhlocarcinodes . 



Five species of Typhlocarcinops have now been described by Miss Rathbun '). The 

 "Siboga" coUected one of these and, besides, two new species. 



Key to the species: 



1. Fronto-orbital width about equal to, or more than, half the 



greatest width of the carapace 2 



Fronto-orbital with much less than half the greatest width of the 

 carapace 6 



2. Postero-lateral margins of carapace parallel or divergent backward 3 

 Postero-lateral margins of carapace convergent backward ; antero- 



lateral margins with three.groups of denticles or with blunt teeth 5 



3. Whole animal sparingly hairy. Eye-stalks almost circular; eye 



faintly pigmented ; orbits somewhat sloping backward. Front 

 widening anteriorly. Antero-external angle of merus of external 



maxillipeds not produced T. ca7ialiculata Rathbun '") 



Animal densely fringed. Eye-stalks piriform. Front not widening 

 distally 4 



4. Dactyli of walking legs regularly decreasing in length from the 



first to the fourth pair; propodites shortened. Eyes faintly 



pigmented or quite pale T. decrescens Rathbun 



Dactyli of penultimate pair of legs distinctly exceeding in length 

 those of preceding and of following pair ; propodites elongate, 

 narrowing distally. Eyes distinct, black, terminal T. angustipes n. sp. 



5. Antero-lateral margins of carapace long, denticulate, "three inter- 



ruptions in the denticles forming three teeth"; surface of 

 carapace rather well sculptured; breadth about 1.3 times its 



length. Eyes pigmented, dark T. marginata Rathbun ^) 



Antero-lateral margins of carapace shorter than postero-lateral 

 ones, very obtuse, with three blunt tubercles, widely separated ; 

 at the level of the posterior tubercles the carapace attains its 

 greatest breadth, which is about 1Y.1 times its length. Eyes 

 faintly pigmented T. transversa n. sp. 



1) A sixth species {T. piroculata) in reality belongs to Typhlocarcinodes. 



2) Proc. Blol. Soc. Washington, v. 22, 1909, p. 112; K. Dansk. Vid. Selsk. Skr., 7. Raekke, Afd. 5, n" 4, 1910, p. 345, pi. 12, 

 f. 16, textfig. 32. Hab. Gulf of Siam. 



3) Proc. U.S. Nat. Mus., v. 48, 1914, p. 152. Hab. Philippines, 27 fathom». The author reraarks in the course of the diagnosis: 

 "this species is the only one of the genus in which the postero-lateral margins converge towards the posterior margin", but on the very 

 page two species are described, in which the same characler is observed, and in one of these (/■. a/igns/ifrons') it is even more pronounced 

 than in 7". marginata. 



63 



