BRITISH FOSSILS. 



Decade X. Plates I. and II. 



GLYPTOL^MUS KINNAIRDI. 



[Genus GLYPTOL^MUS. Huxley. (Sub-kingdom Vertebrata. Class Pisces. Order 

 Ganoidei. Suborder Crossopterygidse. Family Glyptodipterini.) Body elongated, 

 tapering to a point posteriorly. Cranium depressed. Dorsal fins two, distinct, situated 

 in the posterior two-fifths of the length of the body. Ventral fins under the first dorsal, 

 and like the pectorals lobate. The rhomboid scales and the cranial and facial bones 

 ornamented with raised ridges. Teeth of two sizes, composed of (probably) dendro- 

 dentine. Tail diphycercal.] 



Glyptolcemus Kinnairdi. Sp. Unica. 



Specimens of this genus were first described, and their distinctive 

 characters pointed out by me, in a notice inserted in Dr. Anderson's 

 work upon " Dura Den,'' which was accompanied by excellent, 

 though small, illustrative figures, drawn by Mr. Dinkel. 



Since 1859, thanks to Dr. Anderson's zeal and activity, a number 

 of additional specimens, several of great beauty and interest, have 

 passed into the collection of the Museum of Practical Geology, so 

 that I am now in a position to give a tolerably complete account of 

 the structure of these ancient fishes. The singularly beautiful and 

 accurate figures in Plates I. and II. will enable the reader, step 

 by step, to verify for himself the most iDiportant points of my 

 description. 



The body is, as I have said, elongated, and when viewed side- 

 ways, fusiform, tapering to a point at each extremity (Plate I. fig. 1), 

 but when viewed from above or below, though the caudal extremity 

 is still seen to end in a point, the anterior part of the body 

 rapidly widens (Plate I. fig. 3), and ends in a depressed, broad, 

 and shovel-shaped liead, with a semi- elliptical contour, rounded at 

 the snout. 



The length of the whole body is about four and a half times as 

 great as the distance from the end of the snout to the posterior 

 margin of the opercular apparatus ; which distance exceeds by as 

 much as a fourth, or a fifth, the transverse diameter of any 2)art of 

 the body. It somewhat exceeds, again, the perpendicular distance 



Ik. 



