of the Fishery Board for Scotland. 



159 



A few specimens of Lemargus muricatus were obtained on a large sun- 

 fish, Orthagoriscus viola, captured in the Firth of Forth in October 1890. 

 My son (Mr. A. Scott) describes the copepods as burrowing in hollows 

 formed in the flesh of the fish behind the anal fin ; they were not, as in 

 the case of Cecrops, found on the gills. T. Edward has recorded this 

 parasite from the Moray Firth, but it does not appear to have been very 

 frequently observed. 



Lemargus has three-jointed, moderately long and well developed 

 antennules. The antenna? are short, but they are armed with stout and 

 strongly-hooked terminal claws. The mandibles are long and stylet- 

 shaped, and minutely serrated at the distal end (fig. 40). The anterior 

 foot-jaws are very small and armed with short but broad and sharp-pointed 

 terminal claws, finely serrated on the inner edges (fig. 41). The posterior 

 foot-jaws form strong and powerful grasping appendages, as shown in the 

 figure (fig. 42). 



The thoracic feet are all two-branched, but the first and second pairs 

 are not so broadly foliaceous as the others, and approach more to the 

 normal type of feet observed in this group of parasites. In the first pair 

 the outer branches are considerably longer than the inner ones ; but the 

 branches of the second pair, which are short and two-jointed, are sub-equal 

 in length. In the third and fourth pairs both branches consist of broad, 

 one-jointed plates, almost devoid of spines or seta? of any kind. In the 

 fifth pair one of the branches forms a large lamelliform plate, but the 

 other branch is very small and bears at the apex a few minute spines. 



Fam. DlCHELESTIDiE. 



This family includes, according to Dr. Basset-Smith, about 15 genera, 

 but only three or four of them are represented in the British seas, and 

 two are noticed in the present paper. 



Genus Clavella, Oken (1815) 



Clavella hippoglossi, Kroyer. (PI. VII., figs. 1-6.) 



1838. Clavella hippoglossi, Kr., Naturh. Tidsskrift, r. i., vol. i., 

 p. 196, PI. II., fig. 3. 



This, which is so far the only species of Clavella I have observed, has 

 the body very slender and of a reddish colour, the ovisacs are very 

 elongated and of a colour similar to that of the body. We have found a 

 number of these on the gills of large halibut, Hippogossus vulgaris, 

 brought to the Fish Market at Aberdeen. ; they resemble the gill filaments 

 of the fish so closely, both in form and colour, that they are easily missed. 

 It was chiefly by accident they were first observed by us, from noticing a 

 portion of their reddish thread-like ovisacs projecting beyond the ends of 

 the gill filaments. 



The head in Clavella hippoglossi is small and rounded ; the neck is 

 comparatively narrow and indistinctly segmented ; the genital segment is 

 elongated, narrow, and cylindrical, and the abdomen is extremely short. 

 The posterio-lateral angles of the genital segment are produced into small 

 rounded processes, about equal to the length of the abdomen, so that the 

 posterior end has a trilobed appearance. 



The entire length of the specimen figured (fig. 1), exclusive of the 

 ovisacs, is about the seven-twentieths of an inch (9mm). The following 

 are the measurements of another and rather larger specimen : — Entire 

 length of the body, 9 -5mm. ; length of head and neck combined, l'5mm.; 



