482 Prof. Mcintosh's Notes from the 



tionally to the size of the ovaries, seem to arrive at maturity 

 simultaneously. 



The mussels used as bait were found in the stomachs of 

 several, while in the intestine Trophon^ hermit-crabs, and 

 fragments of bivalve moUusks occurred. 



2. On a new Bi'ittsh Staurocephalus (Staurocephalus 

 Siberti). 



When at Whitstable, in June 1884, I noticed in a small 

 aquarium belonging to Mr. Sibert Saunders a minute annelid 

 in considerable numbers, and, as its form seemed unfamiliar, 

 I got Mr. Saunders to forward some to the St. Andrews 

 Laboratory, where they now are. The marine specimens in 

 the aquarium had been procured from the Whitstable oyster- 

 beds, in which Mr. Saunders has for many years taken a 

 prominent interest, so that, in all probability, the species 

 about to be described haunts the algee and other growths 

 attached to the shells ol the oyster. It is very hardy in con- 

 finement, not only living but multiplying in a small aqua- 

 rium, and bearing long journeys without loss. 



This form (PL XIII. fig. 5), which measures about 8 or 

 9 millim. in length and about 1 millim. in breadth, including 

 the bristles, is comparatively pale and semitranslucent, the 

 internal organs, such as the blackish dental apparatus and 

 the straw-coloured or greenish alimentary canal, being- 

 visible from the exterior. There are about thirty segments 

 in the body, exclusive of those devoid of bristles, viz. the 

 cephalic, buccal, first body-segment, and caudal. The tail is 

 terminated by two long slender styles provided with palpocils. 



The head is horseshoe-shaped, and marked along the anterior 

 edge by a series of palpocils, which are of considerable propor- 

 tional length. These organs are broad at the base, taper to 

 . a fine point, and apparently are of great tactile sensibility. 

 Their motion along the anterior arch of the snout is so lively 

 that the surface seems to be ciliated. On the dorsum of the 

 prsestomium in front of each anterior eye is a small tentacle 

 of two segments, the basal shorter than the distal, which is 

 bluntly rounded and furnished with palpocils similar to those 

 on the anterior arch. A pair of tentacles having the same 

 structure occupy a corresponding position on the ventral sur- 

 face of the snout, but they are more external in position, so 

 that they project distinctly on each side. 



The number of eyes is variable ; two are situated externally, 

 each occupying a dimple behind the dorsal tentacle. They 

 are simple pigment- spots, blackish by reflected and pale 



