296 Dr. W. T. Caiman on a 



(Sept. -1, 1S2I^), 15111011011 was living; in Panl *. The fragile 

 and shrivelled specimen had been laid aside as indeterminable 

 when my attention Mas, by chance, directed to Mr. E. J. 

 liliers's description and figures of a form which he assigned 

 to a new genus of rahemonidaj under the name Euryrhynchua 

 Wrzcsnioicshii '], and of which two specimens were obtained 

 from a W(>11 in Cayenne by Prof. Wrzesniowsky, of Warsaw. 

 One of Miers's types exists, in fragments, in the British 

 Museum collection, and a comparison with Burchell's specimen 

 shows that the two are certainly congeneric and possibly even 

 specifically identical. Since, however, there are definite, 

 though not very important, difTcrenccs between the two, I 

 propose to refer to Burcheirs specimen under the new specific 

 name of E. Durchdli. 



The figures given by Miers are somewhat unsatisfactory 

 and his description is incomplete, especially in the absence of 

 any account of the mouth-parts. The genus has therefore 

 remained in obscurity, and, so far as I have been able to 

 discover, the only further reference to it is by Prof. Kingsley, 

 who, in his revision of the Pakemonida3 J, quotes Miers's 

 description and leaves the systematic position of the genus 

 doubtful. In view of this uncertainty, it seems worth while 

 to record the results of an examination of the two specimens. 

 Burchell's specimen, in spite of its great age, was found, on 

 being carefully relaxed, to be in fairly good condition. 



The following diagnosis includes the characters which 

 seem to be of generic importance. 



Family Palaemonidae. 

 Genus Euryruynciius, Miers. 



Rostrum very short, flattened, without teeth above or below. 

 Carapace with an antennal spine, but no supraorbital, hepatic, 

 or branchiostegal spines. Outer flagellum of antennules com- 

 pletely divided. Mandible without a palp. Third maxilli- 

 ])eds slender. Second peraeopods much stronger than the 

 first. 



Type species, E. Wrzesnwwskuy Miers. 



The absence of the mandibular palp brings this genus 

 Avithin a group which lies near the boundary-lino between 

 the Palffimonidas and Pontoniidaj and renders this line, as 



Schenkel has remarked, somewhat indefinite. The fact that 



♦ 

 ♦ Cf. Poulton, Ann. &^Ma}r. Xat. Hist. (7) xiii. pp. 4o-ij6, pi. iii. 

 t I'roc. Zool. Sue. 1^77, p. i'tCd, pi. Ixvii. figs. 2-2 d. 

 X Proc. Acad. Kat. !?ci. riiiladelphia, 1879, p. 424. 



