132 DISCOVERY REPORTS 



of eyes. There is a characteristic pair of divergent nuchal epaulettes reaching back to the 

 3rd chaetiger. The tentacles and tentacular cirri are long and unconstricted. The normal 

 dorsal cirri are about half as long as the body is broad. According to Benham the 

 pharynx extends back to the 7th chaetiger, where it bends forward on itself, and turns 

 back to enter the proventriculus, which occupies segments 10-14. 



The pedal lobes form large, rounded prominences above the bristles, and glandular 

 pads are present on the ventral surface. 



The bristles are bidentate and have the head of the shaft denticulated. Gravier states 

 that there is also in each foot a single, simple capillary bristle. These I have not seen. 



Sacconereis 

 The specimen from St. WS 228 is a ripe female measuring 18 mm. by i mm. for 

 about 70 chaetigers. There are swimming bristles from the 15th to the 35th chaetigers, 

 and the anterior pair of eyes is greatly enlarged, so as to extend down the sides of the 

 head to the ventral surface. Otherwise it is not modified. 



Polybostrichus 

 The specimen from St. 42 is a ripe male beginning to turn into a Polybostrichus. Only 

 the head shows signs of modification. The normal eyes have disappeared and their 

 place is taken by a single pair of dark eyes rather deeply 

 embedded in the sides of the head. The anterior pair of 

 appendages shows signs of forking towards its base, 

 or to be more exact, a pair of stout conical lobes appear 

 to have grown out from the head at the point of insertion 

 of the lateral tentacles and to have carried the latter with 

 them attached to the bottom of their outer faces (Fig. 22). 

 In the light of the controversy as to the homology of the 

 anterior bifid appendages in Polybostrichus it may be F'S- ^2- Autolytus charcoti {Poly- 



, ,-11 11 t bostrichus). Ventral view of head 



worth remarkmg that the true palps do not seem to be ^^.^^ ^^^^^ ^^^ ^^^^^^^ ^^ 



involved in this process at all. Behind these bifid ap- lateral tentacles. 



pendages there is a pair of small, rounded lobes which I 



take to be rudiments of lateral tentacles. The body colour is more intense than in any 



atocous specimen that I have seen. 



Remarks. Of the southern cold-water species A. simplex, Ehlers, A. gibber, Ehlers, 

 A. maclearamis, Mcintosh, and A. charcoti, Gravier, the last is the only one with nuchal 

 epaulettes. 



Autolytus simplex, Ehlers. 



Ehlers, 1901, p. 97, pi. x, figs. 5-8. 

 Fauvel, 1916, p. 430. 

 Monro, 1930, p. 97. 



Occurrence. St. 53 (numerous). 



Specific characters. A very large number of examples of this small species were 



obtained from washings from Hydroid and Mytilus clumps. The size is up to about 



