114 Bulletin, Vanclertilt Marine Museum, Vol. Ill 



have a decided median longitudinal carina, which terminates on each 

 segment posteriorly in a small spine. The telson is short, only two- 

 thirds as long as the sixth segment, tapering, with a decided median 

 longitudinal sulcus ; there is a slight angulation, not a tooth, on each 

 side, midway the lateral margin ; the apex of the telson is very long, 

 acuminate, and there is, on either side near the base of this median 

 tooth, a small, acute, slightly outward-pointing tooth. 



The peduncular article of the caudal fan is small, with a minute 

 tooth at the outer distal angle; the inner blade is intermediate in 

 length between the telson and outer blade, and is narrow ; the lateral 

 margins being approximately subparallel, the distal margin convex, 

 all ciliated; there is a heavy, approximately median longitudinal 

 groove bordered on each side, with a carina. The outer blade is sub- 

 stantially wider and longer than the inner, with a diagonal groove 

 margined by a carina extending from the base to the outer margin, 

 where it terminates subdistally in a small tooth. 



The eye is large, reniform. 



The antennulae have the article beneath the eye concave, with a 

 pointed tip to the lateral portion near the base ; the second article is 

 long, cylindrical, slender; the third article is similar to the second; 

 the flagellum is biramose, the second branch is nearly twice as long 

 as the first. 



The antennae have a short basal joint, a well developed scaphocerite, 

 somewhat longer than the rostrum, with the outer margin thickened 

 and produced to a spine at the distal end, which projects beyond the 

 convex distal margin of the scale of the scaphocerite. The second and 

 third peduncular articles of the antennae are short; the multiarticu- 

 late flagellum is about one and one-third times as long as the entire 

 body of the shrimp. 



The first, second and third legs are chelate, and increase in length 

 in the order named. The fourth and fifth legs are successively long 

 and slender, monodactyl. 



The female thelycum lies chiefly between the base of the fourth and 

 fifth pairs of legs ( See figure ) . 



The very complicated petasma of the male is described by Bouvier, 

 1922, and figured by Spence Bate, 1881 ; also by Senna, 1903. 

 Synonymy. — Peneus longirostris H. Lucas, Explor. Sci. Alger., vol. 1, 



art. 3, p. 46, pi. 4, fig. 6, 1849. 

 Peneus memhranaceus C. Heller, Sitzungsb. Ak. Wiss. Wien, Math- 

 Naturv. CI. B., XLIV, p. 423, taf. 2, fig. 49, 1862.— Die Crust. 

 Sudl. Europa, Wien, p. 296, taf. X, fig. 11, 1863.— J. Y. Johnson, 



