CATALOGUE OF VERTEBRATES. 657 



any benefit conferred by them upon the agricultural interest, 

 however, renders the absence of any fact concerning them of no 

 importance." [C. C. A.] 



CLASS PISCES. 



Fishes. 



SUB-CLASS 



(Cyclostomi.) 



Eel-shaped fishes, without limbs, ribs, jaws ; nasal aperture single 

 and mouth suctorial (circular). 



ORDER HYPEROTRETA. 



Nostril tube-like, penetrates palate; snout with eight barbels; two 

 comb-like series of teeth on tongue; gill apertures far from head. 

 Burrow into the flesh of other fishes. 



Family MYXINID^E. 



Hagfishes. 



MYXINB, L. 

 M. glutinosa, L. (limosa, Grd.) Hagfish. Borer. Sleepmarken. 



No eyes ; two rows of mucous glands below, secreting much 

 slime ; blue above, whitish below. Not abundant on our shores. 



ORDER HYPEROARTIA. 



Nasal duct does not penetrate the palate. 



Family PETROMYZONTID-ffi. 



Lampreys. 



Body naked, cylindrical anteriorly and compressed behind ; mouth 

 armed with horny teeth, resting on papillae; eyes present; seven 



2R 



