Boone, Crustacea, Cruise of "Alva," 1931 159 



The fourth and fifth pairs of legs are monodactyl, similar, with 

 the dactyl acuminate, less than one-third of the length of the 

 propodus. 



References: Palaemon (Parapalaemon) aemulus, Nobili, G., 

 Bull. Paris Mus. Nat. Hist., t. XII, 1906, p. 258 ; Mem. R. Ace. 

 Sci., ser. 2A, t. LVII, 1907, p. 362, pi. 1, figs. 5a-b.— Roux, J., 

 and Sarasin, F., Nova Caledonie: Recherches Sci. en Nou- 

 velle Caledonie et aux lies Loyalty. A. Zool., t. IV, Livr. II, 

 1926, p. 221, text figs. 47-51, Munchen. 



Subfamily: Pontoninae 

 Genus: VANDERBILTIA, new 



Rostrum a broad depressed process with deflexed apex encup- 

 ping the orbit and projecting down on the frontal surface of 

 cornea. Carapace glabrous, devoid of sulci or spines. Eyes with 

 stalk concealed by carapace ; cornea large, well developed. Anten- 

 nulae with basal article laminate; flagella fleshy, as in Palae- 

 moninae. External maxillipeds pediform, with slender exognath. 

 Mandible with two-jointed palp. Antennae with well-developed 

 scaphocerite. First pair of legs weakly chelate, carpal joints unseg- 

 mented. Second pair of legs chelate; propodus expanded, some- 

 what operculiform ; dactyli bi- or tri-unguiculate; epipodite 

 present, well developed. Third pair of legs ambulatory ; dactyli 

 biungulate, inferoiateral margin with accessory spinules in series ; 

 a long slender epipodite present. Fourth pair of legs like the 

 third but without an epipodite. Fifth pair of legs of similar struc- 

 ture to preceding pairs, except that the dactyl is thickened with 

 a basal protuberance, or "hoof" ; no spines present on the infero- 

 iateral margin ; no epipodite present. Abdominal segments glab- 

 rous, resembling Sergestes, sixth abdominal segment one and a 

 half times longer than the fifth. Telson longer than the preceding 

 segment, with three pairs of spines dorsally and three pairs of 

 spine-like bristles distally. Uropoda longer than telson ; outer 

 blade with subdistal tooth and transverse suture beset with den- 

 ticles in continuous series. 



First pair of pleopoda of male with well-developed petasma, 

 consisting of paired organs, united in the median line, strongly 

 resembling Peneu^. Remaining pleopoda two-branched, well 

 developed. \ 



