1G2 Mr. C. T. Regan on the 



Ilister vetustus, Heer, Verh. Holl. Maatsch. Wet. xvi. 58, 

 t. iii. fig. 18 (1862). 



" IF. breviter ovalis, pronoto lateribus unistriato, elytra quinque- 

 striatis, stria suturali nulla." 



Oeningen, Baden (Upper Miocene). 



Note. — Histeridae have been reported from Baltic amber 

 and from the Miocene shales of Florissant, Colorado, but have 

 not been described. The Florissant specimens, collected by 

 Scudder, are in the Museum of Comparative Zoology, Cam- 

 bridge, Massachusetts. Among the fossils collected by the 

 University of Colorado expeditions 1 have not as yet observed 

 any Histeridae ; but very few of the Culeoptera have been 

 critically examined. — T. D. A. C. 



XVI. — The Tlyhrid between the Dream and the Rudd (Abramis 

 brama x Leuciscus erythrophthalmus). By C. Tate 

 Keg ax, M.A. 



[Plates VII. & VIII.] 



FOB some time I have been trying to improve the series of 

 British freshwater fishes in the National Collection ; several 

 anglers and others have helped forward this project by 

 sending char, pollan, vendace, &c, and I am especially 

 indebted to Major H. Trevelyan, from whom I have received 

 a number of fishes from Lough Erne, including several which 

 I regard as hybrids between the bream and the rudd [Abramis 

 brama X Leuciscus erythrophthalmus). 



Smitt (' Scandinavian Fishes/ p. 782) has noted that the 

 rudd is fond of joining as an interloper in the spawning of 

 other fishes (roach, bleak, and white bream), with the result 

 that hybrids are produced. Little appears to be known 

 about the hybrid between the rudd and the common bream, 

 which is in every respect intermediate between the parent 

 species, as may be seen from the subjoined description. 



Abramis brama X. Leuciscus erythrophthalmus. 



Pharyngeal teeth compressed, hooked, entire or more or 

 less crenate, in one or two series, 5 — 5 to 2 . 5 — 5 . 2 *. 



* 5 — o in one specimen, 1 . 5 — 5 . 1 in six, 1 . o — 5 . 2 in one, 2 . 5 — 5 . 2 

 in one, of nine examined. 



