148 Dr Grant wi the structure of' the Lernoea elongata, 



tially buried in the superficial soft parts of marine and fresh- 

 water fishes, while the rest of their body hangs constantly ex- 

 posed to the action of the external element. From this par- 

 tially exposed situation of the LerncBCEy they partake of a mix- 

 ed life, exhibiting in the same individuals a combination of 

 the characters and forms both of entozoa and of insects. Like 

 intestinal worms, they have a simple structure, a soft, naked, 

 and feebly irritable body, they are permanently fixed to the 

 animal, and they live by sucking the internal fluids. From 

 the external situation of the LerncBce, however, they have not 

 only organs for piercing and sucking the animal substance 

 like entozoa, but also parts variously constructed for attaching 

 themselves to the surface of the body like insects ; they exhi- 

 bit the rudiments of antennae, and some of the species are as- 

 serted by BJainville to have sessile eyes. (See Journal de Phy- 

 sique, xcv. 374.) The constant exposure of their body to the 

 vicissitudes of a foreign element has rendered it more consist- 

 ent and stiffer than in those which are always buried in the 

 fleshy substance, and consequently the LerncBcd exhibit the ru- 

 diments of articulations to admit of their necessary move- 

 ments, like the higher animals which have an external or in- 

 ternal skeleton. No articulations are necessary where the 

 animals are composed entirely of soft parts. These affinities 

 with the higher classes of invertebrate animals, which have 

 induced Lamarck to consider the epizoarice as a distinct class, 

 higher in the scale than worms, and which have greatly per- 

 plexed other naturalists in their classification, are well exem- 

 plified in the Lerncea elongata, particularly in the perfect sym- 

 metry of its form, in the great length and regularity of the two 

 tentacula, in the distinctness and firm texture of the head, in 

 the rudimentary antennae and appendices of the mouth, and 

 in the regular form of the body and two ovaria. 



The Lerncea ehngatay which I have so named from its very 

 elongated and slender form, has been several times observed 

 attached to the eyes of the Greenland shark by that enterpris- 

 ing and intelligent navigator. Captain Scoresby, and is men- 

 tioned and figured in his Account of' the Arctic Regions, (vol. i. 

 p. 538, and PI. XV.) as " a singular appendage to the eye"" 

 of that animal. ** To the posterior edge of the pupil of the 



