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Dimensions in mm. l ) : 



Distance between external orbital angles 6.9 



Width between posterior epibranchial teeth 10.1 



Width of front between eye-stalks 2-4 



Length of carapace 8.0 



Length of posterior margin of carapace 5.1 



Length of cheliped 10.25 



Horizontal length of chela 4.75 



Length of palm 3.0 



Height of palm 2.15 



Breadth of abdomen at base 3.1 



Breadth of posterior margin } \ i.S 



[ of penultimate segment of abdomen < 

 Length \ ( 1.1 



Breadth of posterior margin ) \ 1.5 



[ of terminal segment of abdomen <. 

 Length \ ( r.3 



Length of 2d pair of walking lcgs 15.3 



Length 1 l 6.1 



} of meropodite of 2 d pair j 

 Breadth j F ^ | 1.8 



Length of carpo- and propodite j l 6.3 



> of 2 d pair 

 Length of dactylus ) ( 2.0 



The largest specimen measured by Stimpson (a 9) was of about the size of the animal 

 now described. 



Tylodiplax de Man. 

 1895. Tylcdiplax de Man. Zool. Jahrb., Syst, Bd 8, p. 598. 



The lateral margins of the carapace are strongly divergent backward and unarmed, the 

 chelipeds, even in the cf, exceedingly small and weak, and the maxillipeds, the exognath of 

 which is wholly exposed, are auriculate at the antero-external angle of the merus -). 



Two species are contained in the genus, but the systematic place of one of these is doubtful. 

 Key to the species : 

 Front obliquely-defiexed. Carapace with two prominent tubercles 

 on the cardiac region, and two less prominent ones at the an tenor 

 angles of the intestinal region. Chelipeds of c? excessively small 



and weak T. tetratylophortis de Man '■") 



Front not defiexed. Carapace somewhat hairy at the margins, but 

 without the prominent tubercles. Chelipeds of cf somewhat larger, 

 but shorter than most of the walking legs T. indien Alcock 4 ) 



1) Measured under riiicroscope. 



2) De Man states that this genus is distinguished from Clcistostoma by ha ving the merus of the external maxilliped 1 1 

 (longer) than the ischium, but this character is observed quite as vt-ell in the latter gemis. 



3) Zool. Jahrb., Syst., Bd 8, 1S95, p. 599. pi. 14, f. 15. Hab. Penang. 



4) L.c. p. 374. 111. Zool. "Investigator", Crust. prt 10, pi. 64, f. 2. Alcock doubts whether Tylodiplax should not be united 

 with Paracleistostoma or Clcistostoma. The development of the chelipeds in the immature -j" (found at Karachi) rendeis it uncertain 

 whether in the adult form the cheliped should not attain the norrnal size of that the other named genera, but I am of opinion, that even 

 then the shape of the external maxillipeds would justify the maintenance of Tylodiplax. 



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