EUNICIDAE 



131 



the jaws, as figured by Mcintosh, difl'er in many details of structure from those of the 

 present specimens. 



O. sombreriana (Mcintosh), and O. mimita (Mcintosh), are both abranchiate species 

 but with bidentate pseudo-compound bristles. 



Onuphis quadricuspis, M. Sars. 

 Fauvel, 1923, p. 418, fig. 165/-/). 



St. 51. 4. V. 26. OflF Eddystone Rock, East Falkland Island. From 7 miles N 50° E to 7-6 miles 

 N 63° E of Eddystone Rock. 115 m. Gear DLH. Bottom: fine sand. Three specimens. 



St. WS 78. 13. iii. 27. 51° 01' 00" S, 68° 04' 30" W. From 51° 01' 00" S, 68° 02' 00" W to 

 51° 01' 00" S, 68° 07' 00" W. 95 m. Gear DC. Bottom: fine dark sand. Five specimens. 



St. WS 95. 17. iv. 27. 48° 58' 15" S, 64° 45' 00" W. From 48° 57' 00" S, 64° 45' 00" W to 

 4^° 59' 3°" S, 64° 45' 00" W. 109 m. Gear DC. Bottom: fine dark sand, stones and shell. Two 

 specimens. 



LTTITn' 



0-^ 



■"•Imil;! 



T'lmm. 



O 



^0 



a 



Fig. 49. Onuphis quadricuspis. 



a. Tridentate pseudo-compound bristle, b. Smooth pseudo-compound bristle. 

 c. Bidentate pseudo-compound bristle. 



Remarks. All the examples are incomplete. The most perfect has about 40 chaetigers 

 and measures 30 mm. by 2 mm. including the feet. In one specimen there are red trans- 

 verse segmental bands across the back : they are either absent or very faint for the first 

 six chaetigers. The first four to five chaetigers form a kind of neck: the segments are 

 narrow and cylindrical and i| times as long as a segment from the middle of the body. 

 There are two short ovoid frontal tentacles. The inner laterals reach to the 3rd chaetiger 

 and the outer laterals and the median are shorter than these. The buccal segment has 

 a pair of short tentacular cirri inserted on its anterior border behind the inner laterals. 

 The shape of the anterior segments is as usual in the genus. The ventral cirrus is 

 converted into a pad by the 6th 7th chaetiger. The cirriform posterior lip of the chaeta 

 sac disappears about the 17th foot. The fully developed branchia is longer than the 



17-2 



