BORRADAILE— ON CARIDES FROM THE WESTERN INDIAN OCEAN 409 



(16) The gills comprise pleurobranchs for the legs, an arthrobranch for the third 

 maxilliped, and in Hymenocera the vestige of a pleurobranch for the latter limb. There 

 are epipodites on the maxillipeds only. 



A key to the genera of Gnathophyllidse : 



I. Ischium of third maxilliped narrow and moveably sutured to merus. Rostrum 

 of a good length. 



A. Mandible flattened. Lobe of maxilla present. Outer flagellum of antennule 



leaf-like. 



Hymenocera Latreille, 1829. 



B. Mandible subcylindrical. Lobe of maxilla lost. Outer flagellum of antennule 



normal. 



Phyllognathia Borradaile, 1915. 



II. Ischium of third maxilliped broad and marked ofi" from merus by a notch 

 only. Rostrum short. 



[Mandible, maxilla and antennule as in Phyllognathia.] 



Gnathophyllum Latreille, 1829. 



Genus Gnathophyllum. 



20. Gnathophyllum fasciolatum Stimpson, 1860 (Plate 59, fig. 8). 



Proc. Ac. Philadelphia, 1860, p. 28. de Man, Arch. Naturg. liii. i. p. 496 (1888). 

 Abh. Senckenb. Ges. xxv. m. p. 762 (1902). 



Gnathophylhcm zebra, Richters, Meeresf Mauritius, p. 161, PI. 17, figs. 18 — 20 

 and 22 (1880). 



All the specimens are completely bleached. A small antennal spine which is present 

 in my specimens is not mentioned in any description of the species. 



According to Nobili (Mem. Ac. Torino (2), Ivii. p. 305), this species is identical with 

 G. americdnios, and should be known by that name. 



Specimens were taken at Minikoi, Salomon I., and Egmont Reef, Seychelles. 



Genus Phyllognathia. 



21. Phyllognathia ceratophthalma (Balss), 1914 (Plate 59, fig. 9). 

 Hymenocera ceratophthalma, Balss, Abh. k. Bayer. Ak. Wiss. Suppl. Bd. ii. 10, 



p. 54 (1914). 



Phyllognathia ceratophthalma, Borradaile, Ann. Mag. Nat. Hist. (8), xv. p. 206 (1915). 



Dr Balss has kindly communicated to me his opinion that this species is in reality 

 a Gnathophyllum. Its transference to the Gnathophyllidse will probably meet with 

 approval, but in including it in Gnathophyllum some rather considerable differences 

 between its mouth-parts and those of other species of the genus have to be discounted. 

 In the third maxilliped of Gnathophyllum, the ischiopodite is fused with the meropodite, 

 SECOND SERIES— ZOOLOGY, VOL. XVIL 52 



