544 DR. J. G. DE MAN ON CRUSTACEANS [DeC. 1 2, 



9. Distance between the extraorbital angles as long as the length 



of the carapace ; no epigastric lobes affinis. 



3. Both fingers with a tuft of hair proximally 10. 



3. A tuft of hair in the finger-cleft and extending along the fixed 

 finger; carapnce hardly broader than long, depressed ; teeth 

 of the antero-lateral border sharp and salient ; inner angle 



of the wrist produced to form a long spine onyx. 



10. Exognath of external maxillipedes, in the adult male, more 

 than twice as broad as the ischium ; epigastric lobes want- 

 ing; a brush of stitfish hair at the tip of the fixed finger^- . , , .. 



«^^^™^"y {x2.Y.pilosa. 



10. Exognath, in the adult male, not once and a half as broad as 



the ischium 11. 



11. Upper surface of the carapace granulated near the antero- 



lateral margins ; second and third antero-lateral teeth of the 

 carapace not salient; epigastric lobes distinct; granulated 

 ridge behind the frontal border distinctly separated from it 



in the middle puslllus. 



11. Upper surface of the carapace, which is broader anteriorly 

 than that oi jpusillus, not granulated near the antero-lateral 

 margins ; second and third antero-lateral teeth more salient 

 than those of pusillus ; epigastric lobes distinct; granulated 

 ridge behind the frontal margin contiguous to it in the 

 middle line barbattis. 



Artificial key to the known females of the sjDecies of 

 Ptychognathus. 



1. Carapace hardly broader than long, front prominent, nearly 



straight 2. 



1. Carapace decidedly broader than long, front little prominent 



and distinctly sinuous 3. 



2. Regions of the flat, though not particularly depressed carapace 



and epigastric lobes distinct ; antero-lateral teeth of the cara- 

 pace sharp and salient dentatus. 



2. Regions of the much depressed and quite flat carapace hardly ^ _. , ,.. 



indicated ; no epigastric lobes \ "^, ^ **' . 



^ (. andamanicus. 



3. Upper surface of the carapace granulated near the antero-lateral 



margins ; ridge behind the frontal margin distinctly separated 

 from it in the middle ; exognath of external maxillipedes 



distinctlj' less broad than the ischium pusillus. 



3. Upper surface of the carapace, which is anteriorly broader than 

 that of pusillus, not granulated near the antero-lateral 

 margins; ridge behind the frontal margin contiguous to it 

 in the middle; exognath of outer footjaws just as broad or 

 very slightly broader than the ischium harhatus. 



Pal^mon (Eupal^mon) ear Fabr. var. ? (Plate XYIII, 

 figs. 7-19.) 



One male and one female without eggs from a freshwater 

 pool, Christmas Island. 



During the two or three last decennaries seveiul carcinologists 

 have regarded a more oi' less large number of described species of 

 the subgenus Eupalcemon as synonyms or, at the utmost, as 

 individual or local varieties of Palcemon {Eupalcemioii) lar Fabr. 

 (confer: de Man, in 'Notes from the Leyden Museum,' 1879, 

 pp. 168-173; Ortmann, in ' Zoolog. Jahrbiicher (Spengel),' v. 

 Abth. f. Syst. 1890, p. 724; Ooutik-e, in ' Annales Sciences 

 Naturelles,' Zool. 8'"^ serie, t. xii. 1900, p. 292, and other papers 

 of the same authors). Several specimens of Pal. lar Fabr. from 



