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Part III. — Eighteenth Annual Report 



each provided with a large gibbous, cushion-like appendage which seems 

 to arise from the base of the antenna, and to project considerably forward 

 on the under side (fig. 35). These appendages may probably be used as 

 "sucking discs," seeing that the other means of attachment possessed by 

 this copepod do not appear to be very greatly developed. The palpi are 

 small but moderately stout and somewhat cone-shaped. The appendages, 

 which appear to be the posterior foot-jaws, are greatly dilated, clumsy, 

 and unshapely, with a broad cushion-like extremity. 



The four pairs of thoracic feet are all two-branched ; the first pair has 

 the outer branches two-, and the inner apparently only one-jointed ; the 

 inner branches are also somewhat abnormal in shape. The second and 

 third pairs have both branches moderately short and stout and composed 

 of two joints, while in the fourth pair both branches appear to be only 

 one-jointed. 



On one of the topers examined at the Aberdeen Fish Market in 

 October last I obtained a specimen — a male — of a JVogagus-like copepod, 

 which I am inclined to consider as being the male of our Pandarus. 

 (Figure 34 represents the specimen referred to). In some of its structural 

 details this Nogagus closely resembles Pandarus bicolor. The antennae 

 are provided with dilated cushion-like appendages somewhat like those of 

 the Pandarus, but they differ in being armed with terminal claws (fig. 

 36). The palpi are somewhat similar, and so also are the exterior foot- 

 jaws. The posterior foot-jaws differ in possessing a distinct though small 

 terminal claw. All the four pairs of thoracic feet are each two-branched, 

 each branch is two-jointed, and the branches are provided with densely 

 plumose hairs. 



Nogagus, as a genus of copepods, is now to a large extent, if not 

 altogether, obsolete. All the species of which it is composed are repre- 

 sented only by males. Several of these males have already been identified 

 as the males of species belonging to other genera, and those which have 

 not yet been satisfactorily disposed of will, it is believed, be also found 

 to be the males of other species. The Nogagus-like form referred to as 

 found on the toper in the Aberdeen Fish Market, though differing 

 considerably in general appearance from Pandarus bicolor, coincides so 

 closely with it in several of its structural details, that there seems to be 

 little doubt of its being really the male of the Pandarus, 



Habitat, — From what is stated both by Dr. Baird and Dr. Basset- 

 Smith, it would appear that Pandarus bicolor is not confined to Galeus 

 canis* though it seems to be more frequent on that fish. The parasite 

 has been recorded by these authors as occuring also on Carcliarius glaucus, 

 and Scylliwn catulus (the Greater Spotted Dog-fish). 



Genus Lemargus, Kroyer (1838). 



The thoracic feet in Lemargus differ from those of Cecrops in being 

 for the most part broadly foliaceous, and forming at the same time 

 branchial appendages. The intermediate body-segments are smaller than 

 either the anterior cephalic shield, or the posterior lameiliform dorsal 

 plates. There appears to be but one British species of Lemargus. 



Lemargus mu icatus, Kroyer. (PI. VI., figs. 39-42.) 



1838. Lemargus muricatus, Kr. Naturh. Tidsskrift, R. i., vol. i, 



p. 488, Pi. V., fig. 

 1850. Lemargus muricatus, Baird, op. cit., p. 294, PI. XXXIV., 



figs. 3-4. 



1892. Lemargus muricatus, A. Scott, Trans. Nat. Hist. Soc. 

 Glasgow, vol, hi., PI. III., p. 266. 



* This is the same as Squalus galeus, Linn., mentioned by Dr. Baird, and Galeus 

 vulgaris of Day. 



