CIMOLICHTHYS. 47 



depressed bar of bone, about as long as the ectopterygoid but wider than the latter 

 and tapering in front, as well observed from above (PL IX, fig. 12 a). It bears 

 two longitudinal rows of teeth, which resemble those of the ectopterygoid in form 

 and mode of succession. The largest tooth is the hindermost member of the inner 

 series, which is imperfect and accompanied by part of its successor in the original 

 of PI. IX, fig. 10. This tooth is shown by other specimens to have been slightly 

 barbed behind (PI. IX, fig. 12, j\). In advance of it there are about ten shallow 

 tooth-sockets in close series, each ovoid in shape with the longer axis obliquely 

 directed (PI. IX, fig. 11). The teeth occupying these sockets are scarcely known, 

 but there would probably be four or five simultaneously in function. Two of them 

 near the anterior end of the bone in B. M. no. P. 5491 are slightly barbed posteriorly 

 close to the apex. The teeth of the outer palatine series are also imperfectly 

 known; but the incomplete specimen represented from the oral aspect in PI. IX, 

 fig. 11, shows that they must have been about as numerous as those of the inner 

 series and all inclined a little outwards, without any enlarged hindermost tooth. 

 The premaxilla (PL XII, figs. 1 a, 2, pmx.) is an antero-posteriorly elongated thin 

 lamina of bone, tapering at both ends. Its total length is more than four times as 

 great as its maximum depth ; and its outer face, when well preserved (PL XII, 

 fig. 1 a, pmx.), is ornamented by rows of tubercles and discontinuous ridges, which 

 radiate from a point near the upper border at the deepest part of the bone. Both 

 the specimens figured are somewhat flaked and imperfect, and do not display the 

 oral margin. When this is preserved, it is seen to bear a single regular series of 

 very small, slender, conical teeth (B. M. no. P. 1810 a). The maxilla (PL XII, 

 figs. \ <i, 2, riu\) is a long and rather stout bar of bone, without any external orna- 

 ment l)ut displaying its fibrous texture. The premaxilla extends beneath its 

 anterior third, but the hinder two thirds seem to enter the gape of the mouth. 

 There are no traces of teeth in the known specimens. The hinder end of the bone 

 is overlapped by a very small supramaxilla (PL XII, fig. 1 a, srii,v.), which is 

 antero-posteriorly elongated and ornamented with longitudinal tuberculated ridges. 

 The mandible is imperfectly represented in PL XII, fig. 1 a, where its length is 

 shown to be about five times as great as its maximum depth. It tapers very 

 rapidly to the constricted symphysis. The outer face of the dentary {(J.) is marked 

 only by a few delicate smooth ridges, which radiate from the symphysis and are 

 confined to a narrow band on the oral border and to the lower part of the bone. 

 The articulo-angular element (of/.) is antero-posteriorly elongated, and marked on 

 its outer face by a few smooth longitudinal ridges which extend forwards from a 

 point just beneath the mandibular articulation. The oral border of the dentai-y 

 bears three series of teeth, all of which are hollow, conical, and recurved, and 

 firmly fixed at the base in a very shallow socket. The extreme outer margin \& 

 furnished with a single close series of quite minute teeth, of which only the sockets 

 remain in the original of PL IX, fig. 14, but of which a few crowns are seen in 



