riSH-SCALES FROM ECOA SHALES, NEAR LADYSMITH. 229 



Note on Palaeoniscid Fish-scales from the Ecca 

 Shales, near Ladysmith. 



A. Smith Woodward, LL.D., F.K.S., 



Of the Britisli Museum. 



With Plate IX. 



The ganoid scales from the Ecca Shales of Intombi Camp, 

 handed to me for description by Dr. F. H. Hatch, are scattered 

 througrh a hard nodule, but some of them still remain in small 

 groups in their original relative position, and all probably 

 belong- to one individual fish. Their outlines are for the most 

 part distinct, but theii" bony tissue is so thick that nearly all 

 are much splintered, and it is difficult to determine the 

 character of their external surface. They are rhombic in 

 shape, with nearly straight upper and lower borders in their 

 exposed portion, and their most conspicuous feature is the 

 deep pectination or digitation of their hinder border. They 

 are united by a large peg-and-socket articulation which is 

 sometimes very prominent; but, as shown in fig. 1, this arti- 

 culation is not strengthened by any vertical ridge or thicken- 

 ing on the inner face. The extent of their overlap is uncertain, 

 though the shape of the ventral scales suggests that it was 

 considerable. The outer exposed face can only be observed 

 in impressions, which may be partly obscured by concentric 

 growth-lines, which did not originally form surface-markings. 

 The upper and lower thirds of each scale, however, seem to 

 have been ornamented by regular, antero-posteriorly directed 

 ridges, which are finer and more numerous than the hinder 

 pectinations, and are sometimes striated ; while the middle 



