412 Mr. W. Thompson on a new British Fish. 



looking critically to the detailed description of G. argenteolus 

 (fig. 2.), and applying it to the authentic specimen of C. glauca, 

 PI. XVI. fig. 3, there is, with one exception, such a similarity 

 in every character which may be comprised under form and 

 colour, that I am fully persuaded they constitute but one spe- 

 cies. The single discrepancy, like to a specific one, is that of 

 three cirri only being attributed to G. argenteolus ; but as it is 

 much more easy to overlook two than to distinguish all the 

 cirri*, I cannot under the circumstances, and at the same time 

 not forgetting Montagu's great accuracy in description, consi- 

 der this alone a sufficient reason for separation. The localities 

 too, in which only theG. argenteolus and C. glauca are hitherto 

 recorded to have occurred, tend further to favour this view ; 

 by Montagu the first mentioned was obtained on the south 

 coast of Devonshire, where it has not since been observed ; 

 but by Mr. Couch the latter was some time afterwards pro- 

 cured on the adjoining shores of Cornwall. It is in the pre- 

 sent communication that the range of this genus is for the 

 first time shown to extend beyond the south-west of England. 

 Finally, with a full belief of the identity of Montagu's and 

 Couch's fishes, although they have hitherto been regarded by 

 naturalists without any specific reference to each other, I would 

 suggest that the name applied by the former author should be 

 retained, and that Couchia argent eola be applied to the species. 

 Specific characters. — Couchia argent eola. Upper jaw the 

 longer, 5 cirri, four on the upper, one on the lower jaw : ven- 

 trals moderate (from ^ to \ the length of head), and of a 

 whitish colour : sides silvery. 



terior part of the under surface cf the body, and in the smaller by the white 

 extending to the lower portion of the opercle, and here, as well as beneath, 

 faintly tinged, with silver. 



* As before stated, cirri could not be detected in any of the Strangford 

 specimens : lest this should be owing to want of discrimination on my own 

 part, they were submitted to two scientific friends who are well accustomed 

 to the use of the microscope ; but neither could they detect any cirri under 

 it, nor with the aid of a lens: the specimens, it must be remembered, were 

 small. It is only by very close examination that four cirri can be perceived 

 on the upper jaw of the large English C. glauca. "Cirri three, two before 

 the nostrils and one on the skin," are Montagu's words, leaving us in doubt 

 on which jaw he perceived the third cirrus. 



