46 PROCEEDrNGS OF THE NATIONAL MUSEUM. vol. 5;i. 



1. Trunk three and a half times as long as wide; proboscis long and stout; 

 fourth isegment two-thirds as wide as the trunk (9 mm.) 



clavatits Kr^yer, 1SG3, p. 4G. 

 1. Trunk five times as long as wide; proboscis sliort and slender; fourth seg- 

 ment less than half the width of the trunk (9nnn. ) fistula Nordmann, 1S24. 

 1. Trunk seven times as long as wide; proboscis short and stout; fourth seg- 

 ment only slightly narrower than the trunk (G.25 nun.) 



fissiijcs, new species, p. 47. 



PENICULUS CLAVATUS (Muller). 



Plate 1, figs. 1-7. 



Pcnirulns clnvatvs KK0YEn, Bidrag til Kuudskab om Snyltekrebsene, 1S63, 



p. 2CG. pi. 14, fig. S, «-£/. 

 Lvrnuca thivuta Mulleis, Zoologia Danica, 1779, p. 3S, pi. 33, fig. 1. 



Host and record of specimens. — Eleven specimens were obtained 

 from the fins of Sehastes marinus by the United States Bureau of 

 Fisheries steamer Speedwell during the summer of 1878 at stations 

 138, 184, and 198 off Cape Ann, Massachusetts. These 3 lots have 

 received respectively Cat. Nos. 47782, 38028, and 47781, U.S.N.M. 



A single female was taken from the dorsal fin of the same host off 

 Salem, Massachusetts, in August, 1877, and has been given Cat. No. 

 47783, U.S.N.M.. 



Specific characters of female. — Cephalothorax subspherical, as 

 wide as long, a little pointed anteriorly where it forms a bluntly 

 rounded rostrum, to whose lateral margins are attached the first 

 antennae, and to whose anterior margin are attached the larger 

 chelate second antennae; no horns or processes of any description; 

 ventral surface circular in outline and deeply concave, the long pro- 

 boscis being attached to the bottom of the depression. 



The second and third thorax segments form a slender neck, flat- 

 tened dorso-ventrally, chitinized, somewhat enlarged through the 

 bases of the third legs, and bent forward at an angle of 45° just 

 in front of the enlargement. 



Fourth segment two-thirds the width of the trunk, from which it 

 is separated by a deep groove; the fourth legs are attached to its 

 posterior margin. The trunk is cj'lindrical, three and a half times 

 as long as wide, of the same diameter throughout, and abruptly 

 rounded posteriori}'. The abdomen is a minute tubercle close to the 

 dorsal surface, but showing distinct anal laminae, each of which is 

 armed with three long setae and two shorter ones. The ^g'g strings 

 are one-fourth the width of the trunk and nearly twice the length 

 of the entire body. 



The first antennae are turned backward along the lateral margins 

 of the cephalothorax; they are three-jointed, the basal joint the 

 shortest, the second joint the longest, the two terminal joints well 

 armed with setae. The second antennae are stout and unguiculate, 



