87 



shorter than length of carapace. Exognath of ext. maxil- 



lipeds i-/g times as broad as ischium Pt. polleni de Man ^) 



Ext. orbital angle and anterior epibranchial tooth separated 

 by a broad sinus ; distance betw. ext. orbital angles equal 

 to length of carapace. Exognath of ext. maxillipeds 

 exactly as broad as ischium Pi. affinis de Man 



7. Regions on carapace hardly indicated; no epigastric lobes; 



front prominent 8 



Regions on carapace (that is decidedly broader than long) 

 more or less distinct, as also the epigastric lobes ; front 

 not prominent, sinuous 9 



8. Only one tooth behind ext. orbital angle ; carapace distinctly 



broader than long. Outer surface of palm smooth, not 

 hairy. Exognath of ext. maxillipeds scarcely broader than 



ischium Pt. glaber Stimpson ") 



Two teeth behind ext. orbital angle; carapace scarcely 

 broader than long. A brush of stiff hairs at tip of fixed 

 finger. Exognath of ext. maxillipeds twice as broad as 

 ischium Pt. riedelii (A. Milne-Edw.) 



9. Fingers with a tuft of hairs at base of outer surface . 10 

 No tuft of hairs on the fingers 13 j 



10. Surface of carapace granulate near the antero-lateral mar- < 



gins ; epibranchial teeth scarcely indicated ; epigastric lobes " .1 



distinct. Freshwater species Pt. pusillus Heller i 



Surface of carapace punctate or smooth near the antero- j 



lateral margins 11 \ 



11. Anterior margin of front with a double row of granules, I 



confluent in the middle. Merus of ext. maxillipeds 



moderately auriculate, so that the greatest breadth is ^ 



only slightly larger than the length, with the outer ; 



portion of the anterior margin convex; exognath 1^3 



times as broad as ischium. Most likely a marine species Pt. barbatus (A. Milne-Edw.)^) ; 



Anterior margin of front either simple or bimarginate. j 



Merus of ext. maxillipeds with a very large auricle, 

 extended laterally, so that the greatest breadth much 



exceeds the length 12 ^ 



^^ 



1) Ft. pusilhts de Man (nee Heller), Notes Leiden Mus., v. 5, (1883) p. 161; /'/. polleni de Man, Zool. Jahrb., Syst., Bd 9, 



1S95, p. 94, Bd 10, .1S9S, pi. 28, f. 20. Hab. Pasandava Bay (Madagascar). ■ 



2) See DK Man, Weber's zool. Erg. Raise niederl. Ost-Indien, Bd 2, 1S92, p. 324, pi. 19, f. 11; Stimpson, Smitlison. Inst., ' 

 Miscell. Coll., V. 49, 1907, p. 129, pi. 17, f. 5 — 517. Hab. Bouin Islands and Flores. ' 



3) Giiatliogtapsvs barbatus A. Milne-Edwards, Noiiv. Arch. Mus. Paris, t. 9, 1873, P- S'^i P'- '7i f- 4i ^'- /""'I'ol'' Alcock, I 

 I.e. p. 406; Pi. barbatus de Man, Abhandl. Senckenb. Gesellsch., Bd 25, Heft 3, 1902, p. 505; Pt. barhata Pesta, Denkschr. Ak. Wiss. 1 

 Wien, Bd 88, 1913, p. 63. Widely spread, but apparently local, throughout Indo-Pacific region. 



87 ' 



