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Part III. — Eighteenth Annual Report 



of the cephalon or thorax, but the abdomen, which was moderately 

 elongated and cylindrical, was divided into four distinct segments, the 

 first three of which were smaller than the last one ; the last — or anal 

 segment — was about as long as the combined length of the two that 

 preceded it. The caudal furca were short and very divergent, extending 

 outwards at almost right angles to the abdominal segment (fig. 34, 

 PI. XI IT.). The antennules, which showed very little jointing, were 

 very short and stout except the end joint, which was a small one (fig. 

 29, PI. XIIL) The antennae (fig. 30, PL XIII.) were also short and 

 stout, and armed with a moderately strong but short and slightly clawed 

 terminal spine. The mandibles with their palps resembled very closely 

 the figures of these appendages given by Dr. Carm in his interesting 

 work on the marine Copepoda (Les Copepodes du Boulonnais, PL XL, 

 figs. 3 and 4). The biting part of the mandible is armed with five large 

 teeth, arranged widely apart, and several minute, close-set, and slightly 

 elongated spinules, while the palp ends in two short setiferous branches 

 (fig. 31, PL XIIL). The maxillae are broadly foliaceous, the masticatory 

 lobe is armed with a series of spiniform setae along the margin, and 

 a number of stout, elongated plumose setae adorn the margins of the 

 maxilla-palp. The anterior foot-jaws are stout but simple one-jointed 

 appendages furnished with several stout plumose terminal setae (fig. 37, 

 PL XIV.). The posterior foot-jaws (fig. 32, PL XIII.) are moderately 

 stout, and armed with a short but comparatively strong terminal claw. 

 There are also a number of setae on the inner margin of these appendages. 



The first pair of thoracic feet (fig. 38, PL XIV.) are stout and moderately 

 short ; both branches are three-jointed and of nearly the same length, and 

 they are both provided with elongated and densely plumose setae on the 

 inner margins. The next three pairs, which are somewhat similar to each 

 other, have the inner branches short and slender and apparently three- 

 jointed, while the outer branches, which are also three-jointed, are 

 moderately stout and elongate; neither the inner nor outer branches were 

 observed to carry setae, their only armature appeared to consist of one or 

 two minute spines. The fifth feet appeared to be obsolete, but this 

 appearance may have been due to the specimen being somewhat 

 imperfect. 



When it is remembered that the specimen here described was found 

 free amongst a quantity of mixed dredgings, and not in situ in any 

 Ascidian, and that, moreover, from the habitat of the animal its whole 

 structure is more or less flaccid and more liable to injury than the stronger 

 free-swimming forms, it need not be surprising that it should differ to 

 a small extent from the more perfect and better preserved specimens. 

 After a careful study of the characters of this Clyde specimen, I have 

 little doubt that it belongs to the species to which it has been ascribed. 



There does not seem to be any previous British record of Gunenotophorus 

 globularis, and its occurrence in the Clyde estuary is therefore of interest. 



Botryllophilus (?) ruber, Hesse. 



1864. Botryllophilus ruber, Hesse, Ann. Sci. Nat. ZooL (5), t. L, 

 PL XII., figs. 1 and 2. 



I have noticed two, or perhaps three, specimens of a Botryllophilus in 

 some material that was dredged at Tarbert Bank, Lower Loch Fyne, in 

 the vicinity of East Tarbert. The specimens were not found in situ 

 within, any Ascidian, but were mixed up amongst the debris ; their host 

 had probably been damaged by the lip of the dredge so that they escaped. 



According to Dr. Canu, the characteristics of the genus Botryllophilus 

 are shown particularly — First, in the structure and position of the thoracic 

 feet ; second, in the almost constant existence of a single ovigerous sac of 

 a strictly spherical form sheltered between the fifth feet. 



