366 Copepoda living as Messmates with Ascidians. [Sess. 



that my specimens may belong to another species, but I 

 scarcely think so. 



A second species described by Buchholz under the name of 

 Notopterophorus elongatus has been doubtfully recorded as 

 British by Dr Brady, but none of my specimens agree with it. 

 The largest of the specimens from Scapa Flow do not much 

 exceed four millimetres in length. 



Genus Doroixys Kerschner, and 

 Genus Bonnierilla Canu. 



These two genera, which are each represented by a single 

 species, — D. uncinatus Kerschner and B. longipes (Kerschner), 

 — do not appear to have yet been observed in British waters. 

 They both have a general resemblance to species of Boropygus, 

 and are found in similar situations. Dr Canu describes the 

 first as very frequent in Morchellium argus M.-Edw., Circin- 

 alium concrescens Giard, and Polyclinum luteum Giard ; and the 

 other as very common in the branchial cavity of Cynthia 

 lurida Thorell. 



Genus Gunenotophorus 0. G. Costa. 



This genus, like the two last mentioned, is represented by 

 only one species, G. globularis Costa, of which I have only 

 seen a single specimen. This specimen was dredged near 

 Sanda Island, at the mouth of the Firth of Clyde, in 1898, 

 and is described and figured in Part III. of the ' Eighteenth 

 Annual Report of the Fishery Board for Scotland' (p. 387, 

 Plates 13 and 14). Dr Canu, who describes G. globularis as 

 rare, says that it has been found in the branchial cavity of 

 Cynthia lurida and a few other Ascidians. 



Genus Botachus Thorell. 



The only species of Botachus which, up till the present 

 time, appears to have been described is B. cylindratus Thorell. 

 This species, unlike any of those previously referred to, is 

 rather small, slender, and elongated. The average length of the 

 specimens exhibited is about two millimetres. In nearly all 



