387 Part III. — 'Eighteenth Annual Report 



larger size than either Enterocola fulgens, Van Beneden, or Enterocola 

 betencourti, Canu, and which to some extent differs also in some of its 

 structural details from both these forms. I prefer, however, in the mean- 

 time to regard our specimens as a "form" or variety of Van Beneden's 

 Enterocola fulgens rather than institute a new species for their reception. 



These Clyde specimens are found in the intestine — not the branchial 

 cavity — of a small Ascidian. Usually only one Copepod is observed in 

 each specimen of the Ascidian in which the parasites occur, and it also 

 usually so fills up the part of the intestine in which it is lodged that it is 

 with difficulty detached with its ovisacs in situ, one or both frequently 

 breaking away while removing the Copepod from its environment. 



All the specimens of the Copepods obtained as described, and which I 

 have examined, appear to belong to the one species, but they vary 

 greatly in size. The specimen represented by the drawing (fig. 21), 

 measures little more than two millimetres (2- 2mm.) in length, whilst 

 another that I have measured extends to at least four millimetres. The 

 ovisacs are of a distinctly reddish colour, so that when examining the 

 Ascidians in which the Copepods occur one can see at a glance and without 

 dissection whether a parasite is present by the red colour of the ovisacs 

 showing itself through the thin wall of the intestine of the host. 



The mouth-organs of the Enterocola are difficult to make out ; they 

 are all simple, and do not show much structure. Figures 22 and 23 

 represent what appear to be one of the antennules and one of the antennae. 

 The mouth takes the form of a short and somewhat cone-shaped process. 

 There appears to be no mandibles properly so called, and, according to 

 Dr. Canu, the absence of mandibles is one of the distinctive characteristics 

 of the genus Enterocola. The (?) maxillae (fig. 24) are broad foliaceous 

 appendages, bearing on their distal margin a number of stout ciliated 

 spines. The posterior foot-jaws are very stout, and terminate in very 

 short but strong claw-like processes (fig. 25). 



The first four pairs of thoracic feet are all very much alike. They are 

 two-branched ; the outer branches appear to be one-jointed, and are 

 moderately stout, and taper towards the distal end ; they are also 

 furnished with two moderately long and plumose terminal setae; the 

 inner branches consist of short, stout, tapering appendages of a simple 

 and almost rudimentary character (figs. 26 and 27). The fifth pair are 

 conspicuous and broadly dilated appendages. The caudal furca are 

 about twice as long as broad. The female carries two ovisacs, which in 

 well grown specimens are about as long as the body of the copepod. 



Gunenotophorus (?) globularis, Costa. (PI. XIIL, figs. 28-34 ; PI. XIV., 

 figs. 37 and 38). 



1852. Gunenotophorus globularis, Costa, Fauna del Kegno di 

 Napoli, Entom. (1840). 



A somewhat curious copepod, agreeing in almost every detail of 

 structure with the species described by 0. G. Costa under the name of 

 Gunenotophorus globularis, was obtained in some dredged material from 

 the vicinity of Sanda Island, Firth of Clyde, in December 1898. The 

 species is said to occur in the branchial cavity of Ascidians, but this 

 Clyde specimen (only one was obtained) occurred free amongst the 

 dredged material, having probably come from a dredged Ascidian. 



The entire length of the specimen was about five millimetres (about one- 

 fifth of an inch). The body was considerably dilated, but the abdomen 

 was more slender, and was quite distinct ; the whole animal was strongly 

 incurved, as shown by the figure (fig. 28, PI. XIII). The specimen, which 

 had a somewhat macerated appearance, did not exhibit much segmentation 



