Dr. A. Giinther on the History o/ Echeneis. 401 



We have seen above, that the fish named by Mitchill E. albi- 

 cauda is in fact merely an immature specimen of E. naucrates ; 

 consequently this name is a synonym of that species, and cannot 

 be applied to a second, discovered at a later period. Dekay* as- 

 signs this name to the larger species of Sucking-fish found on the 

 coast of the United States. Most of the specimens which he pro- 

 fesses to have examined belong evidently to E. naucrates ; but, as 

 he mentions also fishes with twenty-one lamina?, it is possible that 

 he has confounded that species and E. Holbrookii. Guichenotf 

 appears to have fallen into the same error : he describes a single 

 specimen with twenty-one laminae, caught on the coast of Algiers, 

 as E. naucrates. As this species, however, also shows excep- 

 tionally a number of laminae which is constant in the other, the 

 question can be decided only by an autoptical examination of 

 that individual. Holbrook was the first who described our 

 eighth Echeneis as a separate species J. Although he does not 

 appear to have been aware of its close affinity with E. naucrates t 

 he very properly places it at the side of Elacate ; he is, besides, 

 decidedly of opinion that the firm adhesion of the disk to an- 

 other object is effected by a vacuum produced in consequence of 

 the erection of the laminae. 



9. Echeneis scutata. 

 (PI. X. B.) 



This is a new and most remarkable species, distinguished by 

 the extraordinary size of the disk. Its diagnosis is as follows : 



D. 27 | 22. A. 21-23. 



The length of the disk is contained 2 times in the total length ; 

 the width of the body between the pectorals 5f times. Caudal 

 truncated. Dorsal and anal fins not continued to the caudal. 

 Colour brown. 



Twenty inches long. 



From the Indian Ocean (Ceylon). 



10. Echeneis clypeata. 

 D. 12 | 17. A. 20. 



The length of the disk is contained 3} times in the total, the 

 width of the body between the pectorals 5 times. Caudal subtrun- 

 cated. The lower jaw and the vomer anteriorly with a series of 

 widely-set and strong teeth. The angle of the mouth is situated in 

 the vertical line from the second lamina of the adhesive disk. The 

 length of the ventral is much less than the distance between the 



* New York Fauna : Fishes, p. 307. 



t Explorat. Alger. Poiss. p. 111. 



J Ichthyol. South. Carol, p. 101. pi. 14. f. 2. 



Ann. &f Mag. N. Hist. Ser. 3. Vol. v. 27 



