neio or rare Crustacea from Scotland. 241 



was obtained by carefully washing some masses of Filograna 

 trawled in the Moray Firth. 



Pseudanthessi'us gracilis, Clans. (PL XII. tigs. 15-20.) 



Pseudanthessiiis gracilis, Claus, Arbeit, zool. Inst. Wien, 1889, vol. viii. 

 p. 344, Taf. iv. figs. 1-7. 



Length 1*3 millim. (pg of an iiicli). First body-segment 

 rather longer than broad, gently curving toward the rounded 

 forehead ; last thoracic segment scarcely broader than the 

 slender abdomen. Anterior antenna not reaching to the end 

 of the first body-segment, seven-jointed, the third and last 

 joints much shorter, as shosvn by the appended formula — 



17 . 20 . 8 . 14 . IG ■ 13 ■ 9 

 12 3 4 5 6 7* 



Secondary antenna four-jointed, third joint very small, the 

 last provided with one plain and four elongate and geniculate 

 spiniform setee. Mandibles stout, produced to an acute apex, 

 inner margin evenly convex, middle portion of the exterior 

 margin ciliate. Maxillai simple, bearing three apical seta? 

 (fig. 17). Anterior foot-jaws slender, armed with a few strong- 

 teeth on the upper edge ; a plumose seta springs from the 

 inner edge near the base of the foot-jaw. Posterior foot-jaw 

 three-jointed, second joint somewhat dilated and bearing a 

 stout spiniform seta near the middle of the inner aspect ; the 

 last joint very small and terminated by a stout conical spine 

 and a spiniform seta about three times longer than the joint 

 from which it springs (fig. 19). Inner branches of the first 

 three pairs of thoracic feet three-jointed ; inner branches of 

 the fourth pair one-jointed and scarcely reaching to the end 

 of the second joint of the outer branches, and armed at the 

 truncate apex with two dagger-shaped spines ; the inner 

 branches are without set^e, but there is a small hook-like 

 process near the middle of the inner margin (fig. 20). Fifih 

 pair small, subquadrate, attached to the produced angles of 

 the last thoracic segment, and provided with an elongate 

 dagger-like spine and a plain seta at the apex, and a small 

 seta near the articulation of the joint with the thorax. The 

 first abdominal segment is about equal to the combined 

 length of the next three and is somewhat dilated towards the 

 distal end. Caudal stylets equal to about twice the length 

 of the last abdominal segment ; a small seta springs from 

 near the middle of the outer edge of each stylet in addition 

 to the terminal seta. 



