204 SALMONID^. 



is contained from three times and one-third to three times and two- 

 thirds in the length of the head,. and equal to the extent of the snout. 

 Scales with minute spines, very inconspicuous in young individuals. 

 Coasts of Norway and Scotland. 



/3. Tongue without teeth. 



4. Argentina lioglossa. 



Argentina leioglossa, Cuv. iSf Val. xxi. p. 417, pi. 624; Guichai. Explor. 

 Alger. Poiss. p. 97. 



D. 12. A. 14. P. 19 (22, Guich.). V. 12. 

 The length of the head is two-sevenths of the total, the height of 

 the body one-seventh. The ventral fins are somewhat neaier to the 

 root of the caudal than to the extremity of the snout. ( Val.) 



14. MICROSTOMA. 



Microstoma, Cuv. Regne Anim. 

 Body elongate, cylindrical, covered with large, thin, sUvery scales. 

 Cleft of the mouth very small ; intermaxillaries very small ; max- 

 illaries very short and broad. Eye very large. A narrow series of 

 very small teeth in the lower jaw and across the head of the vomer ; 

 no other teeth. Dorsal fin short, inserted behind the ventrals, but 

 before the anal. An adipose fin is present in most young examples, 

 but freqiiently absent in adult ones ; it is small and narrow, with 

 its extremity fringed or lacerated. Caudal fin forked, the scales ex- 

 tending over its central rays. Pseudobranchiae well developed ; air- 

 bladder large. Pyloric appendages none ; mucous membrane of the 

 stomach with numerous large papillae. 



Marine fishes, not entering fresh waters, from the Mediterranean. 



This genus is allied to Argentina by the structure of its mouth, 

 large eye, large scales, large silvery air-bladder, brown-coloured 

 peritoneum, &c. Its systematic position has been a matter of un- 

 ceKtainty, on account of the absence of an adipose- fin ; for, although 

 Eisso represented this fish with such a fin, Valenciennes declared 

 this to be incorrect. Large specimens, indeed, appear to lose this 

 fin ; our larger specimen does not show a trace of it ; but that it is 

 sometimes present in old examples is shown by the figure given by 

 Risso. In some of our small specimens it is very conspicuous, in 

 others quite rudimentaiy, and in a few I am unable to detect it. 

 Our large specimen is a male ; and although the ovaries have not yet 

 been examined by an Ichthyologist, it is probable that they do not 

 essentially differ from those of Argentina. 



1. Microstoma rotundatum. 



Gasteropelecus microstoma, Risso, Ichth. Nice, p. 356. 

 Microstoma rotuiidata, Risso, Eur. Merid. iii. p. 475, fig. 36. 

 argenteum, Cuv. Sf Val. xviii. p. 358, pi. 544. 



B.4. D. 9-11. A. 8. P. 8. V. 10. L. lat. 52. 



The height of the body is one-tenth or one-eleventh of the +otal 



