714 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.47. 



PARABRACmELLA ROSTRATA (Kr0yer). 



Plate 28, fig. O; plate 56, figs. 249 to 255. 



Brachiella rostrata Kr0yer, 1837, p. 207, pi. 2, fig. 1.— T. Scott, 1900, p. 174, pi. 8, 

 figs. 38 and 39. 



Host and record of specimens. — The United States National Museum 

 collection includes two lots of this species; the first, three females, 

 was taken from halibut near Shetland and was sent by Rev. A. M. 

 Norman, of England, in 1884; they bear Cat. No. 8343, U.S.N.M. 

 The second lot of four adult females with egg strings was obtained 

 from halibut on the Georges Banks by a Gloiicest^r fishing vessel in 

 1883, and bears Cat. No. 6212, U.S.N.M. 



Specific characters o//ema7e." Cephalothorax as long as the trunk, 

 cylindrical, not flattened, and distinctly separated from the trunk by 

 a groove behind the second maxillae; head not enlarged, but covered 

 with a dorsal carapace which is squarely truncated anteriorly; neck 

 about the same diameter throughout; trunk strongly flattened dorso- 

 ventrally, four times the width but only twice the thickness of the 

 neck; two minute conical posterior processes on the ventral surface 

 close to the midline ; egg strings one-half longer than the trunk and 

 narrow; eggs in 10 longitudinal rows, about 40 in the longest rows. 



First antemiae indistinctly four-jointed, with an enlarged base; 

 second antennae biramose and turned down squarely across the 

 frontal margin, the endopod (dorsal ramus) one-jointed with a few 

 minute spines, the exopod (ventral ramus) two-jointed and unarmed. 



First maxillae bipartite with a small palp; second maxillae cylin- 

 drical, tapering toward the tips, where they are joined by a club- 

 shaped bulla, Maxillipeds with a stout basal jomt and a slender 

 terminal claw; the latter is arched dorsally, straight ventrally, and is 

 reinforced on the inner margin near the tip by two secondary spines. 



Color (preserved Inaterial), a brownish-yellow. 



Cephalothorax, 6 mm. long, 1.25 mm. in diameter. Trunk, 6.5 

 mm. long, 4 mm. wide, and 2.30 mm. thick. Egg strings, 8.50 mm. 

 long, 1.25 mm. in diameter. 



Specific characters of male. — Axis of head at right angles to that of 

 the body, the two thoroughly fused, strongly inflated, and without 

 any traces of separation or segmentation; trunk convex dorsally, 

 flattened ventrally, and tapered posteriorly where it ends in two- 

 minute anal laminae, directed diagonally backward and ventrally. 



First antennae slender and three-jointed; second antennae bira- 

 mose, both rami reduced to mere knobs. 



First maxillae tripartite, the palp minute and ending in a single 

 sphie; second maxillae slender but no longer than the maxillipeds; 

 the latter a little stouter and with a stronger terminal claw. 



Color like that of the female. 



