On a neio Lejjtohpid Fish from the Weald Clay. 93 



XVIT. — On a nero Leptolepid Fish from the Weald Clay of 

 Southwater, Susse.v. By A. SMITH WoODWARD, LL.D., 

 F.K.S. 



[riate I.] 



TiiTN cycloid scales which might liave belonged to a Leptolepis- 

 likc fish have already been noticed in the English Wealden 

 formation, bat no complete example of a Wealden member 

 of the Leptolepidaj has hitherto been described. A well- 

 preserved specimen, however, which may be referred to the 

 family just mentioned, has lately been found in the "Weald 

 Clay at Southwater, near Horsham ; and I am indebted to 

 the Directors of the Southwater Brick and Tile Co., Ltd. 

 (through Mr. C. II. Aldersmith, A.M.I.C.E.), for the oppor- 

 tunity of studying this interesting fossil, which has now been 

 presented to the British IMuseum. 



The new specimen is preserved in counterpart in a slab of 

 clay, and its best half is shown of one half nat. size in 

 PI. I. fig. 1. It is exhibited in direct side-view, only 

 lacking the anterior part of the head and the hinder half of 

 the caudal fin. The maximum depth of the trunk is con- 

 tained somewhat less than three times in the length from the 

 pectoral arch to the base of the caudal fin, and would probably 

 fqual about one fifth of the total length of the fish. The 

 same depth is not quite three times as great as the depth of 

 the caudal ])edicle. The fragmentary remains of the head 

 show that tlie mandibular suspensorium is inclined forwards, 

 so that the articulation of the lower jaw must have been 

 directly beneath the hinder part of the orbit. The hyo- 

 mandibular bone {Jim.) bears a long process for the suspension 

 of the operculum {op.), which is shown in impression, trape- 

 zoidal in shape, and about as deep as broad. The preoper- 

 culum {}>op.) has a long upright ascending limb, expanding 

 below into a triangular plate. The suboperculum {sop.), best 

 seen in the counterpart not figured, must have been about 

 four times as broad as deep. Fifteen branchiostegal rays {br.) 

 can be counted, the upper seven being exjjanded and in close 

 scries, the lower eight being narrower bars and more widely 

 spaced. The opercular a])i)aratus is quite smooth, not 

 ornamented. The total number of vertebra3 is about sixty, 

 half being in the abdominal region. The centra are about 

 as long as deep in the anterior part of the caudal region, but 

 are somewiiat shorter than dee[) both in the abdomiiuil and 



