CCELACANTIIUS LEPTURUS. 



19 



The outer surface has an ornamentation composed of minute 

 ridges of enamel^ the ridges having a direction generally parallel 

 with the axis of the ramus. 



In the elongated oval jugular plate (G) of this specimen (Plate 

 lY., fig. 1.), the ridges of the ornamentation are more completely 

 transverse to the axis of the plate than in the specimen No. 3 

 (Plate III, fig. 2). 



The impressions of five strong bony branchial arches are plainly 

 visible on the left side. Minute horny, or osseous, filaments seem 

 to have been set at right angles to the branchial arches along their 

 edges (Plate IV., fig. 1). 



Connecting the branchial arches is a strong median ossification, 

 consisting of an anterior cruciform part, and a posterior elongated 

 spatulate portion. The two anterior branchial arches are con- 

 nected, the one with the outer end, and the other with the base, of 

 a tranverse arm of the cross ; the three other arches unite with 

 the sides of the posterior division, while the long spatulate end 

 lies free between the hindermost pair of arches (Plate IV., fig. 1). 

 Fig 3a. represents a scale of this specimen magnified. 



No. 5. The specimen represented in PI, IV., j^^, 3. 



The under surface of a crushed head of Ccelacanthus lepturus, 

 showing the ornamentation of the jugular plates. In the collection 

 of Edw. Binney, Esq. F.R.S. 



No. 6. The specimen represented in PI. IV., figs. 4 and 5. 



These fragments, figured of the natural size, show, in, fig. 4, the 

 elongated pelvic bones still connected with a part of the ventral 

 fins ; and, in fig. 5, the anterior (D) and posterior (Z)^) dorsal 

 fins, apparently but little displaced from their normal position. 



No. 8. The specimen represented in PI. IV., fig. 6. 



A very perfect hinder moiety of a Ccelacanthus, somewhat 

 larger than any of the foregoing, drawn IJ times the size of 

 nature. 



The persistent notochordal space, with the superior and inferior 

 bony arches and spines, the interspinous bones, and the fin rays, 

 are very clearly displayed. There seem to be 12, or perhaps 13, 

 fin-rays in each lobe of the caudal fin ; and, as in No. 2, the pos- 

 terior fin-rays lie nearly parallel with the axis of the body.^ The 

 jointing of the broad distal portion of these rays in very distinct. 

 The scaly central part of the body (C^) passes backwards into a 

 prolongation about 01 in. wide, also covered with small scales, and 

 beset along its upper and lower margins with small fin-rays, 

 which appear to be simple and unjointed. 



Ccelacanthus Upturns attained considerable dimensions. A spe- 

 cimen obtained by Mr. Molyneux from the Ladies Well Colliery, 



B 2 



