EASTMAN: FOSSIL LEPIDOSTEIDS. 75 
in the total length, in L. platystomus and L. tristechus three and one half, and 
in LZ. osseus with its specialized snout, but three times. The armoring of the 
present species is everywhere lighter and simpler than in the massive L. atroz, 
from which it is readily distinguished by its smooth scales with non-fimbriate 
posterior borders Another peculiarity which is probably of specific import- 
ance consists in the marked elongation of the flanked scales beginning with the 
series in advance of the anal fin and continuing to the tail. Many of the scales 
thus affected are twice as long as they are deep, which accounts for there being 
only 15 oblique transverse scale-series between the base of the tail and base of 
the anal fin, as compared with 21 such series in L. osseus, and 23 in L. trista- 
chus and L. atrox. Owing to flexure of the body with attendant disruption of 
the squamation, it is impossible to state accurately the number of oblique rows, 
but there were at least 45 of them, and possibly 50. 
The head appears to have been nearly severed from the body and turned 
completely over prior to fossilization, thus exposing the visceral surface to 
view. This was not accomplished without injury or displacement of certain 
parts, as witnessed by the position of the left palatine, which shows its oral 
surface adjacent to the right frontal (above in the figure), while the right man- 
dibular ramus, hyoid arches, and interoperculim are transported to the opposite 
side of the head (below in the figure). Back of the last-named element 
is seen from visceral aspect the left clavicle, a strong bone similar in all 
respects to that of recent gars. The interoperculum differs from the correspond- 
ing bone in L. atrox in. wanting a postero-inferior process, and it is relatively 
much lighter as well as somewhat smaller. Neither of the maxille are pre- 
served, and but one of the mandibular rami; this, the right-hand one, is 
turned downward so as to conceal most of the teeth, but the articular facets are 
well shown, and appear exactly as in L. tristechus. Little more can be said of 
the cranial bones, owing to their confused position and the fact that none of 
them differ in any appreciable respect from those of recent species. 
Of the vertebral column fourteen centra lying in natural order are visible back 
of the head, their length increasing rapidly from 0.55 cm., beginning with the 
first, to 0.85 cm. The fins are relatively weaker than in L. atroz, especially 
the caudal, which has fewer short rays , and the dorsal and anal are more 
remote. The radial formula is as follows: D. 7 (-8?); C. 12; A. 7 (-8?). 
TABLE OF MEASUREMENTS. 
Length of mandibularramus. .. . 5 6 oO. oo co UE Gm. 
Mens tbrofimberoperculumesee see ere al ae a OF 
Length of hypohyal ee ya Ot he eae eon 0S. 
lbenno Gaeiglnel 6 co 6 6 56 0 5 6 o goo o HS 
Length of epihyal Neen ase erst ae cei on tse is 2 LO 
saint or Gene ¢ 6 io () o be A) ceece (o eouecetc Mion ob 
Heirhtoticaudalipediclonwsele is) se | OO 
Width of basioccipital concavity . . . . . A sy otba dd le 
Distance from basioccipital concavity to vomer . . . . 16.0 
