MACRUBOUS DECAPODA OF THE SUDANESE RED SEA. 385 



Nobili's as distinct from Dana's. The most important difference between the 

 present specimens and P. tridentata is brought out in the table of measure- 

 ments of the second pair of legs given above. In my specimens, and also in 

 those examined by Dana and Nobili, the merus is longer than the carpus. 

 In Borradnile's figure of P. tridentata it is shown as considerably shorter 

 than the carpus. On the other hand, the proportions of the joints of the first 

 legs in P. tridentata agree closely with the present specimens. 



As a result of the above considerations, it follows that the present 

 specimens belong to the same species as those examined by Nobili and 

 referred by him to P. tenaipes, Dana. I accept Nobili's identification- 

 P. tridentata, Borradaile, is closely allied to P. tenaipes and doubtfully 

 distinct. 



Distribution. Previously recorded from the Red Sea by Nobili ; Sulu Sea 

 (Dana) ; Japan (Ortmann) ; Maldives (Ortmann) ; Amboina (De Man). 



Genus Periclimenes, Costa. 

 Periclimenes petitthouarsii (Audouin, 1826). 



Paleemon petitthouarsii, Audouin, 1826, Deser. Egypte, Hist. Nat. I. iv. p. 91 ; Saviguy, 



Atlas, Crust., pi. 10. fig. 3. 

 Periclimenes petitthouarsii, Borradaile, 1898 6, p. 381 : and 1917, p. 369. 



Localities. Station V. A, one, 1G mm. Station V. C, two, 13 and 15 mm. 

 Station VII. E, one, 11 mm. Station VII. C, four, 10-15 mm. 



Sudan Coast, no definite locality, forty, 7-18 mm. 



Distribution. Previously recorded from the Red Sea by Audouin, Paulson, 

 Kossmann, and Nobili, and by the latter from the Persian Gulf. 



Periclimenes calmani, n. sp. (PI. 27. fig. 11 ; PI. 28. figs. 14-15.) 



Locality. Sudan Coast, four specimens, 13-17 mm. 



Description. The carapace is smooth, without supra-orbital spines. Antennal 

 and hepatic spines are present, the latter a little below the level of the former. 



The rostrum (PI. 27. tig. 11) reaches almost or quite to the apex of the 

 antennal scale and considerably beyond the apex of the antennular peduncle. 

 It is concave from the base and bears dorsally 8-9 teeth, the proximal tooth 

 well behind the orbit, the second tooth placed over the orbit, and the remainder 

 more or less regularly spaced with a longer interval between the 5th and 

 6th tooth. The lower edge bears 4-5 teeth, the proximal one below the 

 5th tooth of the upper edge. 



The third maxillipeds reach to the end of the antennal peduncle. The 

 exopod is longer than the antepenultimate joint. The latter bears six spinules 

 and a few setae on its outer margin. The first legs (PI. 28. fig. 14) extend 



