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XVI. On a new Species of Ccelacanthus (C. Tingleyensis)/ro?ra the Yorkshire Cannel 

 Coal. By James W. Davis, F.L.S., F.G.S. 



(Plates XLVI.-XLIX.) 



Read Juno 19th, 1884. 



SPECIMENS vary very much in size, and occur in all stages of growth between 

 3 inches and six times that length ; their form is somewhat long and slender, with a 

 series of powerful fins well adapted for rapid progression through the water. Examples 

 which appear to have attained the maximum size of ahout 18 inches in length are taken 

 for the following descriptions. In such a one the head occupies one fourth the entire 

 length, the body, from the pectoral arch to the base of the tail, two fourths, and the tail 

 the remaining fourth. The greatest depth of the body is immediately behind the pectoral 

 fins, where it is 35 inches ; posteriorly the depth diminishes gradually to the base of the 

 tail, which is 2 inches. The hody was probably more or less cylindrical in form, and the 

 lateral diameter little less than that between the dorsal and ventral surfaces. The 

 anterior portion of the caudal fin expands to a diameter of 4 inches, and the rays radiate 

 from the base 3 inches : beyond this the second portion of the tail extends about 1*3 inch, 

 its termination supporting a second series of rays, forming the peculiar prolongation of 

 the caudal appendage characteristic of the genus. In addition to the caudal tin there are 

 seven others — two dorsal and one anal fin, a pair of pectorals, and a pair of ventrals. The 

 posterior dorsal fin (PL XLVI. d 2 ) is located 2 - 5 inches in front of the caudal (c 1 ), and is 

 supported by a scale-invested lobe from the body. The anterior dorsal fin (d l ) is about 

 3 inches in front of the posterior one : in several specimens where this fin is present 

 there does not appear to be any lobe supporting it. The pectoral fins (p) are situated 

 immediately behind the thoracic arch, and, like the ventrals (v) and anal («), they are 

 lobate. The ventrals are powerful and large fins, placed opposite the space intermediate 

 between the two dorsal fins. The anal fin, 3 inches behind the ventrals, is situated at 

 a considerably shorter distance from the caudal than is the posterior dorsal fin. The 

 whole of the body is invested in a covering of comparatively thin, enamelled, and 

 beautifully ornamented scales ; those on the dorsal and lateral regions are broader 

 and have a more obtuse termination than those on the ventral surface. The scales 

 covering the lobes of the fins are smaller than those of the body, and are proportionately 

 thinner. The head is protected by dermal ossifications, the surface of which is covered 

 with enamel raised into, and arranged in, an exquisite series of parallel but sinuous 

 ridges. The external covering of the head is preserved in many specimens, but in all cases 

 more or less crushed and disturbed. The cranial bones include frontals (/), parietals (p), 

 and occipitals (o) : a restored outline of their forms, one half the natural size, is 

 attempted on PL XLIX. fig. 2, from which it may be inferred that the several bones 



SECOND SERIES. — ZOOLOGY, VOL. II. 64 



