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Lateral maro-ins of carapace subparallel or feebly convergent 

 backward; in the latter case mesogastric region smooth . 3 



3. Carapace with very strong transverse folds across the whole 



breadth, the anterior folds fringed with hairs lying flatly 

 on the carapace and averaging in length half the space 



between the folds 4 



Carapace with feeble transverse striae, that do not extend 

 across the median parts of the carapace 5 



4. Lateral margins of carapace faintly convergent backward. . P. plicatus (H. JMilne-Edw.) 

 Lateral margins of carapace subparallel ; striation coarse . . P. fakaravensis Rathbun ^) 



5. Front scarcely declivous, wholly visible from above. Lateral 



margins of carapace scarcely convergent backward, concave. 

 Meropodites of two last pairs of legs with only one sub- 

 distal spine at posterior margin. Propodites of penultimate 



pair of legs four times as long as broad P . planifrons de ^lan 



Front distinctly declivous. Lateral margins of carapace some- 

 what convergent backward, straight. Meropodites of all the 

 walking legs with 2 — 3 subdistal .spines at posterior margin. 

 Propodites of penultimate pair of legs only three times (or 

 less) as long as broad 6 



6. Distance between e.xternal orbital angles i^s times the length 



of carapace. Postfrontal lobes four in number. Inner margin 

 of ischium of external maxiUiped straight; inner angle of 



merus obtuse, less produced P . propinqtiiis de Man ") 



Distance between external orbital angles 1^.3 times the length 

 of carapace. Postfrontal lobes seven in number, the median 

 one very small, triangular. Inner margin of ischium of 

 external maxilliped concave; inner angle of merus more 

 produced ^ .... P. laevis Borradaile *) 



7. Distal posterior angle of meropodites of last pair of legs 



rounded. Front with a prominent tooth at angle. . . . P. crassipes Randall *) 

 Distal posterior angle of meropodites of last pair of legs 

 dentate. F"ingers of cheliped with a reddish-brown patch in 

 the middle of the outer surface P. transversus (Gibbes) ") 



Mem. Mus. comp. Zool. Harvard Coll., v. 35, n" 2, 1907, p. 29, pi. 5, f. i, pi. 9, f. 6— 6a. Hab. Paumotus. 



2) Rec. Ind. Mus. Calcutta, v. 2, prt 3, 1908, p. 216, pi. iS, f. 2. Hab. brackish water at Port Canning (Lower Bengal). 



3) Proc. Zool. Soc. London, 1900, p. 592, pi. 42, f. 7. Hab. Funafuti. 



4) Literature: Ki.ngsley, Proc. Ac. Nat. Sc. Philadelphia, 1880, p. 199. Description: de Man, Notes Leiden Mus., v. 12, 1890, 

 p. 86, pL 5. f. II. Hab. Pacific region. 



5) Literature and description: de Man, Miim. Soc. Zool. France, igoo, p. 52, pi. 2, f. 9. Throughout all tropical regions, but 

 chiefly Atlantic. 



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