108 Bulletin, Vanderbilt Marine Museum, Vol. Ill 



as long as the sixth segment, tapering, triangular, with a very acu- 

 minate apex, and a decided median longitudinal sulcus. The rhipi- 

 dura is very well developed with a strong, short base, the inner blade 

 extending beyond the telson for nearly half its length with the distal 

 margin unequally rounded, a median longitudinal ridge; the outer 

 blade is of similar shape to the inner, but longer and slightly wider 

 with an oblique ridge on the upper surface and the outer lateral 

 margin nearly straight. 



The eye-stalk is of moderate size, the cornea reniform, set obliquely 

 terminal, very convex, nearly spherical, black. 



The antennulae have the basal article long, excavate beneath the 

 cornea, and giving rise on the inner upper proximal region to an 

 elongate, flexible, tongue-like process which widens slightly distally 

 and has the free end rounded; the entire margin ciliated, and the 

 process extends to midway the second joint, which is thickened, two- 

 thirds as wide basally as long, with a longitudinal line of cilia on the 

 upper surface; the third joint is very small, short. The flagellum is 

 biramose, both branches very short, composed of short rings. 



The antennae have all the peduncular articles very short, the 

 scaphocerite lobate, with the outer margins thickened, nearly straight 

 except near the tip, the inner lateral margin convex, narrowing near 

 the tip, which lacks but little from being triangular. 



The first, second and third legs are chelate ; the fourth and fifth 

 pairs are monodactyl; all five pairs increase slightly in length from 

 the first to fifth pairs. 



The male petasma is figured (see text figure 2 A and B). 



The female thelycum is also distinctive. 

 Synonymy. — Peneus hrevirostris Kingsley, Proc. Acad. Nat. Sci. 

 Phila., vol. 30, p. 98, 1878.— Rathbun, Proc. Wash. Acad. Sci., 

 vol. 4, p. 287, 1902. — Hakriman, Alaska Exped., Crust., vol. 10, 

 p. 146, 1904.— ScHMiTT, Univ. Calif. Publ. Zool., vol. 23, p. 21, 

 fig. 9 a-e, 1921. 

 Peneus calif orniensis Holmes, Occas. Papers Calif. Acad. Sci., vol. 7, 

 p. 218, pi. 4, figs. 64-69, 1900. 



Genus : PENAEOPSIS Spence Bate. 



Penaeopsis kishinouyei (Eathbun). 



Plate 33, text fig. 3, A, B. 



Type: The type and additional specimens were taken at Tagus 

 Cove, on the reef north of Tagus Hill, Albemarle Island, Galapagos, 



