STRUCTURE OF LERNEOPODA DALMANNI. 85 



intestinal canal commences behind the antennae, by a trumpet-shaped mouth. 

 It passes backwards and upwards towards the convex dorsal aspect, then curves 

 downwards and forwards towards the ventral aspect, and ends abruptly close to 

 the oral opening. In the cavity of the bod}'- there are numerous collections of 

 oil drops, especially towards the posterior end of the larva. The eye-spots are 

 situated on the dorsal aspect, not far from the anterior margin. Two large 

 branched masses of dark-red granules may be seen, one close to the eye-spots- 

 the other farther backwards ; and in the free larva these masses are connected 

 by long streaks of reddish pigment. 



The further development of the larva we have had no opportunity of ob- 

 serving. 



Addendum, June ^Uh. — When we read our paper before the Royal Society, 

 none of the more typical and best-known species belonging to the genus Lerneo- 

 poda had come under our notice. Since that time, through the liberality of Mr 

 Robert Brown, we have had the opportunity of examining three specimens of 

 the L. elongata, which were obtained by him attached to the eye of a Greenland 

 shark {Scymnus borealis) caught in Ponds Bay, Davis' Strait, in the summer 

 of last year. 



We have especially directed our attention to the distal extremities of the 

 arms, with the view of making a comparison between the mode of attachment of 

 this species to the cornea of the shark, and that of L. Dalmanni to the skate. 

 The arms of L. elongata taper abruptly at their distal ends, and are connected to 

 a small, rounded, horny, or chitinic disk. This attachment is evidently of a very 

 close and intimate description, for in attempting to separate them from it, the 

 substance of the arms gave wa}^ rather than permit the connection between them 

 and the disk to be severed. We could not say with absolute certainty whether 

 the structures composing the arms were anatomically continuous with that of the 

 disk, but there were appearances which led us to suppose that the chitinic in- 

 vestment of the arms was continuous with that of the disk. The arms them- 

 selves are evidently not united at their tips, except through the medium of the 

 common plate to which they are both connected. In our specimens we saw no- 

 thing to lead us to suppose that the arms were inserted into the substance of the 

 cornea, as is stated by Baird* to have been the case in the specimen he examined, 

 for the disk was undoubtedly attached to the surface of the cornea. Of the two 

 eyes of the shark obtained by Mr Brown, one had two parasites connected ta it, 

 the other only a single one. But each cornea had, in addition, a number of circular 



* British Entomostraca, p. 334. 

 VOL. XXIII. PART I. 2 A 



