GNATHOPHYLLUM PANAMENSE. 147 



ber of rostral teeth appears to vary somewhat. In two males in this Museum 

 the number is four above and one below. In Risso's original description and 

 figure * the rostrum is represented as bearing six teeth above. In the same 

 author's later description oi this animal t the rostrum is said to bear six teeth 

 above and one below, wliile in the accompanying figure (Plate I., Fig. 4) 

 there are five teeth above and one below. Milne Edwards :}: describes the 

 rostrum as armed with six to seven teeth above. 



G. panamensc, like O. ckgans, is very gaily attii-ed. A colored sketch of 

 the former species, drawn from life by Mr. Westergren, represents the gen- 

 eral ground color of the body to be a dark brown, ornamented with a multi- 

 tude of whitish spots, among which are sixteen red spots regularly arranged 

 as shown on Plate E, Fig. 1. The rostrum, eyes, and antenna3 are pale ochre 

 (the flagellum of the second antennaj orange), the fifth and sixth abdominal 

 segments, telson, and swimmerets are also ochre. The basal joints of the 

 second pair of chelipeds are violet, the merus, carpus, and fingers ochre, the 

 basal part of the propodite orange. The third, fourth and fifth pairs of legs 

 are violet. According to Risso and Heller, G. degans is spotted with golden- 

 yellow, and otherwise differs in details of coloration from its western relative. 

 In the form described by Gourret § as G. clegans, var. brcvirosiris, from Mar- 

 seilles Bay, the ground color is bi'ick-red. 



Length, 22.5 mm. ; length of carapace, including rostrum, 7.5 mm. 



Taken on the reef at Panama, at low tide, March 12. One ovigerous 

 female. 



Gnathophi/llum fasciokdum Stimps.,|| from Australia and Amboyna, agrees 

 very closely in form with G. elcgans, but differs wholly in the pattern of its 

 markings and in coloration from both G. elcgans and G. panamensc. G. zebra 

 Richters,* fi-om Mauritius, is without much douljt the same as G. fasciolatmn. 

 Ortmann f has lately recorded a Gnatliophjlhmi from Tahiti as a new species, 

 G. pallidum. It differs from G. fasciolatum only in the absence of color- 

 marks. This difference may be due to the action of alcohol. 



In the genus Gnafhoph//llum, the external flagellum of tlie antennule is 

 double, producing a short third flagellum similar to that of the Palcemonidce. 



* Hist. Nat. des Crust, des Euvirnns de Nice, p. 93, Plato II., Fig. 4, 1816. 

 t Hist. Nat. de I'Eiirope Merid., V. 71, 1826. 



j Hist. Nat. des Crustaces, II. ;5G9, 1837. 



§ Comptes Rendus, CV. 1034, 1887. 



II Proc. Acad. Nat. Sci. Pliila., 1860, p. 28. 



* Beitr. zur Meeresfauna der Insel Mauritius und dcr Seychelleii, p. 161, Plate XVII. Pig. 18-20, 1880. 

 t Zoolog. Jiilirb,, Abth. f. Syst., V. 537, 1890. 



