72 ACONTIOFHORUS. 



Some of the setae of tlie basal joints are very stout and 

 almost spine-like. Mandible (fig. 10) simple, filiform ; 

 palp consisting of one long simple seta. Maxilla two- 

 lobed (fig. 11), one lobe minute and bisetose, the other 

 larger and furnished with three long plumose setae. 

 Posterior antennae and foot-jaws nearly like those of 

 A. scutatits. Fifth foot (fig. 15 a, a) composed of one 

 broad subovate branch and bearing five long marginal 

 setae. Abdomen (female) of three segments, the first 

 constituting more than half the length of the abdomen, 

 and composed of two coalescent somites ; second seg- 

 ment scarcely half as long, posterior angles of both 

 produced backwards and overlapping the succeeding 

 segment ; third segment about as long as the second ; 

 caudal appendages scarcely longer than broad, each 

 bearing five plumose setae, the largest of which are 

 longer than the abdomen. Length xe^^ ^^ ^^ i^ch 

 (1"6 mm.). 



Two specimens only found, both dredged off the 

 Yorkshire coast, near Scarborough and Robin Hood's 

 Bay. 



The word ornatum was applied to this species by a 

 misprint in the ' British Association Report,' and is 

 not properly applicable ; armatum was chosen for the 

 specific name with reference to the spinous setae of 

 the anterior antennae. 



