BRITISH FOSSILS. 



whatever but that the species is distinct from all the Fachycormi 

 hitherto discovered. 



Description. — The species of Pachycormus to which Endadis 

 has the nearest resemblance is Pachycormus curtus, from the has 

 of Whitby. The figure given of this species in the ''Poissons 

 Fossiles " represents a fish nine inches in length by three inches in 

 depth. The specimen under description is also nine inches in 

 length, but was probably an inch longer when perfect ; the depth 

 is only two inches and three quarters. The diameter of the caudal 

 pedicle at a corresponding point in the two specimens is one inch 

 in Pachycormus curtus and two inches in Endactis. The dorsal 

 fin in the latter is longer and the rays thicker, and the ventral 

 and anal fins are more approximated. Compared with Pachy- 

 cormus gracilis, the body is shorter and the head comparatively 

 smaller. It has no resemblance to any species of Pachycormus 

 found associated with it in the Lyme Regis beds. The bones of 

 the head are much crushed, and the operculum is thrown upwards 

 from its position ; the latter disturbance makes the head appear 

 larger than it is in reality. It is in fact small for the size of the 

 fish. In form it approaches that of an isosceles triangle, the lines 

 of the forehead, and lower jaw being very slightly curved, the snout 

 forming the apex of the figure. The mouth is large, the lower jaw 

 measuring an inch and a half in length. The teeth are wanting. 

 The branchiostegous rays are numerous. Judging from what re- 

 mains of the pectoral fin, it probably corresponded in size and 

 X structure with the analogous organ of Pachycormus. The dorsal fin 

 is situated six inches from the snout, and is immediately over the 

 insertions of the ventral fins. It contains at least twenty rays. 

 Of these the four or five anterior ones are single, and increase 

 consecutively in length. They are, however, true rays, carried 

 upon interneural spines, and not fulcral scales. The principal 

 fin rays are transversely jointed at rather distant intervals. The 

 ventral fins are small and indistinct. The anal fin commences one 

 inch and a half behind the attachment of the ventral fins. The 

 interhsemal spines supporting the anterior rays of this fin are very 

 strong. The fin rays are thicker than in any of the Pachycormi. 

 The number cannot be discerned, but those that remain correspond 

 in character with the dorsal fin rays. The scales are very numerous. 

 In the neighbourhood of the scapular arch they are rhomboidal, 

 with the posterior angles slightly rounded. In the afterpart of the 

 fish they become curvilinear. They are invested with a thin layer 

 of enamel, on the surface of which an elegant pattern is produced 



