1985.] NATURAL SCIENCES OF PHILADELPHIA. 175 



c 3 . Second legs remarkably shortened (carpal joint and hand to- 

 gether not longer than the merus). Gills seven. 5 



d l . Second legs chelate . . Pontophilus. 



d 2 . Second legs not chelate Sabinea. 



6 2 . Eyes wanting. Second legs not chelate, rather robust, with 

 fringes of long, plumose seta} A spiny median crest on the cara- 

 pace Prionocrangon. 



'/.,. Several pairs of legs wholly obsolete. Rostrum elongated. 



Paracrangon. 



PONTOCARIS Bate, 1888. 

 Bate, Challenger Macrur. 1888, p. 495. 



Very nearly allied to Crangon, especially to Sclerocrangon. 

 Second periopoda not remarkably shortened, carpus and pal ma 

 together longer than the merus. Six pleurobranchise (i-o) and one 

 podobranchia (h) present (see Bate, 1. c, p. 496). Carapace with 

 seven keels, the five uppermost dentate. Abdomen sculptured. 



Oy. Anterior lateral angles of carapace projecting forward. Rostrum 

 acuminate P. propensalata. 



a.,. Anterior lateral angles of carapace obliquely directed outward and 

 forward. Rostrum bidentate P.pennata. 



1. Pontocaris propensalata Bate, 1888. 



Bate, Challenger Macrur. 1888. p. 496, pi. 90, figs. 2, 3, pi. 85, fig. 5. 



Geographical distribution: Ki Island, near New Guinea, 140 

 fath. (Bate). 



2. Pontocaris pennata Bate, 1888. 

 Bate, ibid., p. 499, pi. 91. 



Geographical distribution: Arafura Sea, 49 fath. (Bate). 



CRANGON Fahricius 1798 (restrict). 



Fabricius, Suppl. Entomol. Syst., 1798, p. 409 (pr. part). Kingsley, Proceed. 

 Acad. Nat. Sci. Philadelphia, 1879, p. 412. 



Second perciopoda not remarkably shortened, with chehe. Eyes 

 present, free. Five gills present: four pleurobranchise (1. m. n. o.), 

 one arthrobranchia (k.). fi 



5 The number of gills has not been examined in all species. I found five 

 gills in: Crangon boreas, salebrosus. intermedins, typicus, ajfinis. francis- 

 corum, Nectocrdngon lav, and seven in Pontophilus norvegicus, Sabinea 

 septemcarinata. By other authors ( Bate, Smith) are recorded five in Crangon 

 agassizi, and seven in Pontocaris propensalata, pennata, Pontophilus bre- 

 virostris, abyssi, challengeri, Sabinea hystrix. 



6 Smith records in Cr. agassizi a pleurobranchia on k, but no arthro 

 branchia. The branchial formula given by Bate (1. c, p. 482) 

 wrong. 



is certainly 



