154 Dr Grant 07i the LerncBa clongata. 



largest species are known to abound. Many species of this 

 animal have been described and figured by Muller, Linnaeus, 

 Bosc, Bruguieres, Ocken, Lamarck, Lesueur (Jour, of Phi- 

 ladelphia)^ and Blainville, but the species above described ap- 

 pears to have escaped their notice. The most obvious cha- 

 racters of the L. elongata are two simple cylindrical tentacula 

 longer than the body ; head distinct, ovate, depressed, with 

 four small antennae, two serrated hooks, and a circular mouth 

 in form of a proboscis ; body subclavate, ventricose, simple, ter- 

 minated above by a narrow neck, and broad and lobed at the 

 base ; two ovaria longer than the body, thick, straight, cylin- 

 drical, and exhibiting through the outer covering hexagonal 

 ova disposed in perpendicular rows. 



Plate II, Fig. 5, represents the Lerncea elongata twice the 

 natural size, adhering by its tentacula to the outer surface of 

 the transparent cornea of the shark. 



«, The horny extremities of the tentacula buried and ce- 

 mented together under the surface of the cornea. 



6, The compressed origin of the tentacula from the under 

 and back part of the head. 



c, The anterior pair of knotted antennae. 



dy The narrow neck most distinct on the back part. 



By The anus, 



J] The oviduct. 



gy A hard flat pointed prominence above the mouth. 



\ The cyHndrical proboscis. 



i, The anterior point of the head. 



Z, The horny serrated base of the jointed hook or lateral 

 jaw. 



w, The fleshy peduncle of the hook or jaw. 



w, w. Two very small and soft filiform antennae. 



o. Minute opening on the fore part of the base of the abdo- 

 men. 



p, p, Lower rounded terminations of the two ovaria. 



q. Numerous diseased circular spots on the cornea. 



