34 



Crax Alector, L. ; while in external characters the bird approaches 

 the Crax globicera, L., from which it is distinguished by the redness 

 of its cere and by a prominence on each side under the base of the 

 lower jaw, in addition to the globose knob near the base of the 

 upper. The tube in the Crax Yarrellii is straight throughout its 

 whole length, except a short convolution imbedded in cellular 

 membrane placed between the shafts of the os Jurcatorium. The 

 trachea is narrow, and the fold, invested and supported by a mem- 

 branous sheath, gives oft* one pair of muscles, which are in- 

 serted externally below the apex of the os Jurcatorium. The lower 

 portion of the tube, immediately above the bone of divarication, 

 sends off a pair of muscles to be inserted upon the sternum. The 

 upper pair of muscles (furculo-tracheal) influence the length of the 

 tube above the convolution. The inferior pair (sterno-tracheal) 

 have the same power over the bronchial tubes and that portion of 

 the trachea which is below the convolution. 



Several specimens were laid on the table of a Clupea taken in the 

 mouth of the Thames, which Mr. Yarrell regarded as distinct from 

 the commonHerring of our coasts, the Clupea Harengus, Linn. He 

 dedicated it to Dr. Leach, who, he was informed, has often stated 

 that the British coast possessed a second species of Herring. The 

 Clupea Leachii is much deeper in proportion than the common Her- 

 ring, an adult fish 8 inches long being 1 inch ^ths deep, while a com- 

 mon Herring of the same depth measures 10^- inches in length. The 

 dorsal and abdominal lines of the new species are much more con- 

 vex; the latter is keeled, but has no serration. The under jaw has 

 three or four prominent teeth placed just within the angle formed 

 by the symphysis : the upper maxillce have their edges slightly cre- 

 nated. The eye is large. The scales are smaller than in the other 

 species, and there is no distinct lateral line. The back and sides 

 are deep blue with green reflections, passing into silvery white be- 

 neath. The dorsal fin is placed behind the centre of gravity; but 

 not so far behind it as in the common Herring. The number of the 

 fin-rays and of the vertebrcz differ in the two species as follows : 



D. P. V. A. C. Vertebra. 



Clup. Harengus 17 . . 14 . . 9 . . 14 . . 20 56 



Clup. Leachii lfc . . 17 . . 9 . . 16 . . 20 54 



The new species differs also from the common Herring in flavour, 

 being much more mild. It is now full of roe, while the adult com- 

 mon Herrings ceased spawning in November, and having retired 

 subsequently to the deep waters are not at present to be met with 

 on the southern coast. Mr. Yarrell added, that there was reason to 

 believe that a third species of Herring, of a larger size than either of 

 the others, occurred sometimes on our eastern coast. He also men- 

 tioned that he had obtained last summer from the Thames, the 

 two Shads regarded by M. Cuvier as the Clupea Alosa, Linn., and 

 the Clupea Jallax, LaCep. 



Mr. Yarrell stated that he had received a letter from Mr. Dill- 



