BORRADAILE— ON THE PONTONIIN^ 377 . 



Genus PoNTONiOPSis Borradaile, 1915. 



Ann. Mag. Nat. Hist. (8), xv. p. 207. Potts, Proc. Camb. Philos. Soc. xviii. 

 p. 59 (1915). 



Definition: Body rather slender, compressed but with the cephalothorax somewhat 

 flattened dorsally; rostrum short, shallow, lanceolate in dorsal view, toothless; a sharp 

 antennal spine, but no hepatic or supraorbital spines ; eye subspherical, with large 

 cornea ; outer flagellum of antennule not deeply cleft ; antennal scale broad ; mandible 

 without palp ; second maxilliped without podobranch, its last joint mediad of preceding 

 joint ; third maxilliped with vestigial arthrobranch, narrow in all joints ; legs short, 

 directed outwards, rather stout, second pair very unequal, the smaller of the type of the 

 first pair, the larger with long, stout, parallel-sided palm and short fingers, dactylo- 

 podites of last three pairs stout, curving at tip to simple end-claw. 



Type: Pontoniopsis comanthi Borradaile, 1915 (Plate 57, fig. 27). 



Ann. Mag. Nat. Hist. (8), xv. p. 213. Potts, Pap. Dep. Mar. Biol. Carnegie Inst. 

 Washington, viii. p. 81, PL 1, fig. 3 (1915). 



Pontoniopsis sp. Potts, Proc. Camb. Philos. Soc. xviii. pp. 59, 62 (1915). 



Definition : Rostrum reaching end of second joint of antennular stalk, with slight 

 keel above and deeper keel below, straight, its breadth much greater than its depth, 

 about equal to greatest width of eye; basal joint of antennule broad, its expansion 

 consisting of two broad spines, of which the .foremost ends in the distal spinule and 

 the hinder is the stylocerite, second and third joints broad and flattened, second longer 

 than third, its distal angles sharp, flagella short, outer cleft to moderate depth ; 

 antennal scale outreaching antennular stalk, broad, with stiaight outer and convex inner 

 sides, and subrectangular end, which is not nearly reached by the small distal spinule; 

 antennal stalk outreaching basal joint of antennule, with basal spine well developed ; 

 third maxilliped not reaching end of antennal stalk, its last two joints subequal, 

 together shorter than preceding joint ; first leg outreaching antennular stalk by hand 

 and wrist, arm and wrist subequal, hand rather shorter, fingers shorter than palm, 

 hairy; longer leg of second pair outreaching antennular stalk by hand, wrist very short 

 and wide, with a sharp process below at the end, hand about equal to preceding three 

 joints, fingers much shorter than palm, bearing interlocking teeth ; last three legs hairy 

 at end, with stout dactylopodites curving at the top rather strongly to form a sharp 

 end-claw; telson rather narrow, blunt ended, shorter than uropods. 



Length of longest specimen, 8 mm. 



Torres Straits, on Comanthus. 



Genus Periclimen^us Borradaile, 1915. 



Ann. Mag. Nat. Hist. (8), xv. p. 207. 



Definition : Body rather stout, decidedly compressed, without sudden change in 

 curvature of abdomen, suggestive of Alpheus ; rostrum rather short, straight, with 

 SECOND SERIES— ZOOLOGY, VOL. XVII. 48 



