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



the dull hue of the latter presenting quite a contrast to' the 

 colour of the other, which is of as brilliant a silver as any of 

 the Clupeiadce. Its general organization too is much more de- 

 licate than that of the Motella : in the form of the head they 

 are different ; in C. glauca, the separating line between the 

 opercle and pre-opercle, both of which are silvery and some- 

 what hard, is conspicuously marked ; in the Motella the oper- 

 cle appears exteriorly undivided, in consequence of its soft 

 and fleshy covering. The snout of C. glauca is shorter than 

 that of the other, and the mouth smaller ; this is differently 

 formed from that either of a Motella or Clupea, but possesses 

 numerous sharp and curved teeth along both jaws. Its rictus 

 is in a line with the first third of the eye ; that of the M. quin- 

 quecirrata with its posterior margin. No pores are apparent 

 within the posterior line of the opercle, as in the species just 

 named, but a row of them surmounting the upper lip. The 

 difference in the ventral profile is considerable, all the speci- 

 mens of C. glauca being, from the protuberance of the belly, 

 very convex anteriorly, — an appearance which the Motella 

 does not present. 



When announcing this species in the ' Magazine of Natural 

 History,^ (vol. v. p. 15) Mr. Couch founded a new genus 

 upon it, which he called Ciliata; but subsequently, in the 

 works of Mr. Jenyns and Mr. Yarrell, it appeared as a Motella. 

 Although its possessing the very few characters assigned to 

 this genus may be considered sufficient to place this fish un- 

 der it, the comparison of specimens, of which the result has 

 been given, induces me to think that it should constitute a 

 new genus. It participates in the characters both of Clupea 

 and Motella, resembhng the former in its silvery brilliancy*, 

 and in almost instantly dying on removal from the water 

 (which the latter genus can long survive): its form, posterior 

 to the head, is precisely that of Motella, with which it hke- 

 wise accords in possessing cirri. In selecting a generic name, 

 that of Ciliata should, by reason of its priority, be adopted, 

 were it not pre-engaged f. Such being the case, I propose, 



• It lias a metallic appearance, as if covered with silver-leaf, wholly un- 

 like the silvery whiteness of the lower portion of the body in some of the 

 Gadidce, as Gad. minutus, Merlangus vulgaris, &c. 



t Cities, which may, 1 think, be considered equivalent to Ciliata, though 



