MACKUROUS DECAPODA OF THE SUbAtiESE RED SEA. 387 



Periclimenes sp. ? 



Locality. Uncertain, one specimen, broken, labelled " Sommensal, P.O. 13." 

 Remarks. I cannot identify the single mutilated specimen with any 

 described species and I think that it represents a new form. As the second 

 pair of legs and the posterior half of the abdomen are missing, I refrain 

 from giving it a name. Among described forms it appears to be most closely 

 allied to P. borradailei, Rathbun = P. tenuipes i Borradaile, nee Holmes, and 

 to P. kolumadulensis, Borradaile, 1915. 



The rostrum, which is slender and slightly recurved at the tip, extends 

 beyond both the antennular peduncle and the antennal scale, and is one and 

 a quarter times as long as the carapace measured dorsally. The rostral 



formula is —^- ' The carapace bears supra-orbital, antennal, and hepatic 



spines. Such of the legs as remain still attached to the specimen are 

 exceedingly long and slender. The first pair extend beyond the apex of the 

 rostrum by the whole of the chela. The carpus is one and a quarter times 

 as long as the chela. The fifth leg reaches forward as far as the apex of the 

 antennal scale. This specimen differs from both P. borradailei and P. kolu- 

 madulensis in the shorter rostrum and different rostral formula and in the 

 presence of a supra-orbital spine, but resembles both in the slender form of 

 the legs. 



Peeiclimenes sp. ? 



Locality. Station VII. C, one specimen, 9 mm. 



Remarks. This specimen cannot be identified with certainty as the second 

 pair of legs is missing. It belongs to the subgenus Falciger and to that 

 group of species having antennal and hepatic, but no supra-orbital, spines on 

 the carapace. The suborbital angle of the antero-lateral border of the 

 carapace is acute but not spiniform, and the lower angle sub-rectangular. 

 The rostrum is long, equal in length to the dorsal line of the carapace 

 from the border of the orbit, and extends forward to the same level as the 

 tip of the antennal scale and far beyond the antennular peduncle. It 

 bears seven teeth (including the terminal one) on the upper margin and 

 two teeth on the lower. All the upper teeth are situated on the rostrum 

 itself, the first one immediately above the orbital border, and there are none 

 on the carapace. The antennal scale is about three and a half times as long 

 as broad at its widest part, and the external margin ends in a strong spine 

 which extends beyond the apex of the scale. The antennular peduncle 

 reaches forward to the level of the fifth tooth of the rostrum. It has one 

 spine only on the external distal corner of the basal joint and a prominent 

 spine on the ventral surface of this joint near the middle of the outer margin. 

 The last three thoracic legs seem unusually stout. 



