Dr. A. Giinther on Deep-sea Fishes. 17 



Coal-measure fish of which Prof. Young gave the first de- 

 scription, and which is now so widelj known under the name 

 which he applied to it. But as the law of priority is now- 

 a-days considered to be inexorable, I must, though much to 

 my regret, propose the abolition of '' Amijliicentrum^'' retaining, 

 however, '■'' 'pes-rance^'' M'Coy, and '"'' Qranidosum^'' Young, 

 as distinct species of the genus Cheirodus. 



EXPLANATION OF PLATE III. 



Fig. 1. Palatal aspect of a skull of Dipterus from Thurso, in the Hugh- 

 Miller collection, n, anterior nasal notch ; n', posterior nasal 

 notch ;^i!, palato-pterygoid ; pa.sph, parasphenoid ; qu, quadrate; 

 X, facet for mandibular articulation ; ti.ch, notochordal opening ; 

 /. m, foramen magnum ; b, one of the marginal plates of the 

 external cranial buckler, seen fi-om its inner surface. 



Fiff. 2. Mandible of Dipterus, seen from above, a large amount of the 

 matrix being left between the rami. Hugh-Miller collection. 

 d, dentaiy; ag, angular; ar, articular; sp, splenial, with its 

 dental plate. 



Fig. 3. The same specimen, seen from below, y, y, lateral labial fosste ; 

 the other letters as in fig. 2. 



Fig. 4. The same specimen, seen from the right side. Lettering as in the 

 preceding figures. 



Fig. 5. Palcedaphus insignis, Van Ben. & De Kon., seen from above; one 

 fourth natural size, and taken from a plaster cast. Lettering as 

 in the figures of Dipterus. 



Fig. 6. The same, seen from below. 



Fig. 7. The same, seen from the left side. Compare this figure especially 

 with the similar view of the mandible of Dipterus^ fig. 4. 



II. — Preliminary Notices of Deep- Sea Fishes collected during 

 the Voyage of H.M.8. ' Challenger.^ By Dr. Albert 

 GiJNTHER, F.R.S., Keeper of the Zoological Department, 

 British Museum. 



As some time must elapse before the second part of the 

 Ichthyology of H.M.S. ' Challenger' (which will contain an 

 account of the deep-sea and pelagic forms) can be published, 

 it is proposed, with the sanction of the Lords Commissioners 

 of H.M. Treasury, to publish preliminary diagnoses of the 

 genera and species which are new to science. The materials 

 collected have proved to be far more extensive than was at 

 first anticipated ; and the author has great pleasure on this 

 occasion to express his gratification at the admirable manner 

 in which the specimens have been preserved by the gentlemen 

 intrusted with their care, and at the clear and simple method 

 in which all necessary particulars connected with their cap- 

 ture have been noted. 



A7in. & Mag. N. Tlist. Ser. 5. Vol. ii, 2 



