(ill 



25. Orchomenella ciliata, G. 0. Sars 



(PI. 25, fig. 2). 

 Trypliosa ciliata, G O. Sars, Oversigt over Norges Crustaceer I., p. 81, PI. 3. fig. 4. 



Body comparatively short and stout, Lateral corners of cephalon 

 rather projecting and broadly rounded in female, somewhat narrower in male. 

 Coxal plates of moderate size, the 4 anterior pairs about twice as deep as the 

 body; 1st pair scarcely expanding below; 5th pair about as deep as broad, 

 infero-posterior angle but slightly produced. Last pair of epimeral plates of 

 metasome rounded at the infero-lateral corners, posterior edge smooth. First 

 segment of urosome with a deep transversal depression dorsally. Eves rather 

 large, oval, widening below, pigment light red. Superior antennas with the 

 1st joint of the peduncle very large and thick; nagellum only slightly exceed- 

 ing the length of the peduncle and composed in female of 8, in male of 12 

 articulations, the 1st of which is very large and densely ciliated, especially 

 in the male; accessory appendage scarcely half the length of the flagellum, 

 3-articulate, 1st joint large, slightly dilated and furnished with dense fascicles 

 of slender setse on the lower edge. Inferior antennae in female but little 

 longer than the superior, in male about half as long again. Epistome 

 flattened in front and not projecting beyond the anterior lip. Anterior gnatho- 

 poda rather robust, propodos a little longer than the carpus and slightly ta- 

 pering to the transversely truncated extremity. Posterior gnathopoda not very 

 slender, propodos oval, fully half as long as the carpus and obtusely produced 

 beneath the minute dactylus. Pereiopoda comparatively short; basal joint of 

 the 3 posterior pairs, and especially that of the last pair, rather expanded 

 and nearly as long as the remainder part of the leg. Last pair of uropoda 

 in female with the inner ramus shorter than the basal joint of the outer, tip 

 bidentate, outer one with 3 slender setce on the inner edge. Telson rather 

 broad, triangular, with a single pair of dorsal denticles, cleft very narrow, 

 extending beyond the middle. Colour greyish white, without any distinct 

 pigmentation. Length of adult female scarcely exceeding 5 mm. 



Remarks - I first described this form as a Tri/pho*<t owing to its 

 general resemblance to the species of that genus. On closer examination of the 

 oral parts I have, however, now found, that it cannot properly be referred 

 to that genus but must be regarded as a true Orchomenella. 



Occurrence. - - The only place where I have hitherto met with this 

 species is outside the sandy beaches of Jaederen, south coast of Norway. It 

 occurred here rather sparingly in comparatively shallow water together with 

 Bafhyporeia pilosa, Lindstrom. 



Distribution. - Coast of France (Chevreux). 



10 Crustacea. 



