THE GENUS SALARIAS. 79 



pression, they may be moved by the fish, independently 

 of each other, like the keys of a harpsichord : they are 

 nearly all from the Indian Ocean, and present two distinct 

 modifications. In the sub-genus Salarias Cuv. properly 

 so called, the dorsal fin is high and deeply cleft ; and the 

 sides of the mouth are generally furnished with strong 

 canine teeth : but in Erpicthys Nob., the dorsal fin is 

 nearly of equal breadth throughout ; and the canines are 

 wanting : many species arrange themselves under each of 

 these, which appear the two typical sub-genera. The next 

 is Rupiscartes, at once distinguished by having an 

 eel-shaped form, and four rays to its ventral fins ; a 

 structure without example in this family except 

 only in Opistognathus. The fourth is Cirripectus, which 

 shows us the chironectiform type, in its semicircle of 

 t€ntaculi, or cirri, round the mouth and nape, analogous 

 to Cirribarbus. Lastly comes Dr. Riippel's sub-genus 

 Petroscertes, joined indeed to Blennichus by M. Valen- 

 ciennes, but at once distinguished by a single series of 

 small setaceous teeth, without the large canines of 

 Omobranchus Ehr. (^Blennichus Val.): this form, in 

 short, as seen in O. filamentosus (Jig.'2,\.), connects the 





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genus Salarias m the most perfect manner with that 

 of Blennius. It thus appears, that the sub-genera of 

 Salarias and Blennius not only represent each other, 

 but also show us a series of analogies to the BlennincB 

 and the ClinincB ; a fact which will be at once ap- 

 parent, if we arrange all these in columns, and com- 

 pare those groups which stand opposite to each other. 



