270 ini. A. SMITH woodwabd on [Feb. 16, 



to the coroiioid region. The quadrate bone {qu.) is clearly thrust 

 between the pterygoids as in the last specimen, and its thickened 

 hinder border is preserved. An imperfect impression of the 

 cranial roof (c.r.) seems to indicate a narrowing between the 

 orbits. The characteristic operculum (op.), suboperculum (s.0^5.), 

 and 12 branchiostegal rays ('>?'.) are also imperfectly shown in 

 impression. Of the vertebral centra only fragments are preserved 

 in the abdominal region — nearly all are indicated in impression. 

 The centra are very short and deep in the abdominal region and 

 the anterior half of the tail, but relatively longer more posteriorly. 

 Their sides are marked by fiue longitudinal ridges, and the few 

 centra preserved immediately behind the head are much laterally 

 compressed by crushing, as if they were not well ossified. Eighty 

 centra can be counted before they become as long as deep, 

 and the impression of the hinder half of the tail is not qidte 

 clear. The neural and haemal arches are extremely delicate, and 

 much inclined backwards. There are no traces of the pectoral 

 fins ; but there are fragmentary remains of the pelvic pair and 

 their supports entirely in advarce of the dorsal fin. The latter 

 arises about opposite the thirty-fifth vertebra and shows seven 

 rays, ^^ith uncertain evidence of an additional one in front 

 and behind. The distal bifurcatious of the middle rays are 

 preserved. The anal fin, extending about half the total length of 

 the fish, arises nearly opposite the forty-ninth vertebra. Its rays 

 are extremely numerous, but are not sufficiently distinct in the 

 hinder part to be counted ; the foremost rays are apparently 

 thickened by the sliding apart of their right and left halves. 

 Along the ventral border of the trunk there is a narrow streak in 

 which a chain of scutes or abnormally developed scales can be 

 recognized on parts of the caudal region (Z.). 



A third specimen in counterpart (Plate XVIII. fig. 3) exhibits 

 the head and the greater portion of the trunk, with an especially 

 conspicuous display of the ventro-lateral row of enlarged scales just 

 mentioned. On one side of the fossil an impression of the cranial 

 roof is distinct (c.r.) showing the truncated occiput, the nearly 

 parallel sides of the otic region, and the slender rostral region, but 

 none of the sutures. There is also some indication of an interorbital 

 constriction, but this may possibly be a false appearance due to the 

 crushing of the parasphenoid upon the roof. Traces of the striated 

 suboperculum are distinguishable ; and several branchiostegal rays 

 occur on the opposite side of the specimen. The crushed, short, 

 and delicate vertebral centra are distinguishable ; and in the caudal 

 region the almost filamentous neural and hsemal arches are 

 observable, all much inclined backwards, and those at the hinder 

 end of the fossil clearly inclined to the axis of the fish at a much 

 more acute angle than the short supports of the anal fin. The 

 remains of only six rays are shown in the dorsal fin. The pelvic 

 pair are crushed together and imperfectly seen from above or 

 below ; about twelve rays can be counted in the patch they form. 

 The precise characters of the enlarged scales of the conspicuous 

 ventro-lateral series (?.) cannot be determiued, but some appear to 



