NO. 2135. NEW PHILIPPINE CRABS— RATHBUN. 545 



trimcjite pteiygostomian tubercles, the anterior one the largest. The 

 short, slender, acuminate rostral horns are spread wide apart and 

 are slightly curved or convex to each other. The orbital coverings 

 are large and prominent; preorbital hood very thin and sharp-edged, 

 the anterior angle acutely pointed, the posterior angle with a blunt 

 tooth; anterior margin of postocular cup with a very small tooth. 

 Basal segment of antenna wide and armed at the anterior angle wdth 

 a slender spine pointing directly forward and in large part visible in 

 dorsal view ; the margin behind it is longitudinal up to a slight lobe 

 beyond which there is a deep sinus and a tubercle. 



Chelipeds (of female) short and weak, margins of palms parallel, 

 outer surface crossed by longitudinal lines of pubescence, fingers 

 with an almost imperceptible gape at base. Ambulatory legs orna- 

 mented with long spatulate bristles on the margins; dactyli long and 

 slender, their spinules relatively small. 



Relationship. — This species is perhaps nearest to 11. vemicosipes 

 (Adams and White) ^ which has similar though not identical orna- 

 mentation on the carapace ; H. verrucoslpes is definitely set apart by 

 the very elongated postocular cup and by the supplementary plate 

 projecting sideways from the basal segment of the antenna. 



HYASTENUS BIFORMIS, new species. 



Type-locality. — Tawi Tawi Group, Sulu Archipelago: Tinakta 

 Island (N.), N. 82° W., 1.4 miles; lat. 5° 11' 50'' N.. long. 110° 54' 

 E.; 10 fathoms: co. S.; Feb. 21, 1908; station 5159, Altjatross. 



Holotype.—Mixle. Cat. No. 48217, U.S.N.M. 



MeasureTJients. — Length of carapace on median line, 9.8; length 

 of rostral horns, 3.5; width of carapace, 7. 



Carapace oblong-triangular, high in the middle, cardiac higher 

 than gastric region and bearing two prominent tubercles side by side, 

 and behind them and lower down a median, fiat tubercle; gastric 

 region Avith two median tubercles, the posterior of which is larger 

 and higher, and a tubercle on either side not far from the orbital 

 sinus; an arch of three small tubercles near the margin of the 

 branchial region, of which the posterior one is the largest, and is 

 pointed ; a single tubercle on the intestinal region and on the hepatic 

 margin ; a row of several tubercles on the subbranchial and sub- 

 hepatic regions, and another row on the pterygostomian region. 

 Rostral horns slender, widely separated by a U-shaped sinus, mod- 

 erately divergent. Preorbital hood with a small tuberculiform point 

 at the anterior angle ; anterior margin of postocular cup cut into two 

 subequal lobes. Basal segment of antenna broad, armed with two 



1 See Caiman, Trans. Linn. Soc. London, ser. 2, Zool., vol. 8, 1900. p. .3(5, pi. 2, figs. 

 23, 24. 



10600°— Proc.N.M.vol.50— 16 35 



