1891.] Geology and Paleontology. 655 
ception that it lacks the head. Its generic position is therefore not 
positively determinable, although it is strongly suggested by the 
parts preserved. If not strictly a species of Sardinius, it is an allied 
form. The vertebrz have longitudinal fosse ; the hypural bones are 
well developed, and distinct from each other. The dorsal fin com- 
mences above the ventrals, and is of moderate length; anal not elon- 
gate. The spaces between the caudal hzemal spines are traversed by 
a slender rod obliquely downwards and backwards near the vertebre. 
The scales are cycloid and with strong concentric grooves. Owing to 
the loss of many of the scales, the presence of a lateral line cannot be 
affirmed. One interneural in front of D. I. 
Char. specif.—Radii, D. 1-7 (possibly one lost at the end); A. 8; 
V. crowded together, but not less than six. Caudal vertebre, 17. 
Depth at D. I entering length to bases of caudal rays, 1.5 times. 
Depth of caudal peduncle, 2.25 in the same, Length from front of 
base of D. to end of caudal fin, 29 mm. Length of caudal vertebral 
series, 20mm. Vertical depth of caudal fin, 22 mm. Length of base 
of dorsal fin, 6 mm. ; elevation of do. 8 mm, 
PROBALLOSTOMUS LONGULUS, gen. et. sp. nov.—? Isospondylorum. 
Char. gen.—Mouth small, ? superior, at the extremity of a prolonged 
muzzle. Dorsal vertebre elongate, fossate ; caudal vertebre shorter. 
Pectoral fin median, lateral; dorsal above ventrals, median; anal 
small; caudal large, little emarginate. No conspicuous spines. 
Hypural bones distinct from each other. It is probable that the single 
species known is either scaleless or that the scales are extremely minute. 
The affinities of this genus are not exactly determinable, owing to the 
injured condition of the head. It may be allied to either of the two 
genera already enumerated. The remarkable production of the muzzle 
distinguishes it from either, as well as the elongate vertebræ, and 
corresponding width of the intercostal spaces. 
Char. specif—Radii, D. I 8; C. 6 21, a; A, 16; V se: P 
10. There is a break behind the skull, so that the number of dorsal 
vertebre is uncertain ; there were at least 1 3; caudal vertebrz, 18. 
The form of the postcranial regions is slender, the depth at the dorsal 
fin entering that region to the base of the caudal fin six times, and the 
total length ten times. The head enters the total minus the caudal 
rays, one and three-fifths times, or twice, including the caudal fin. 
The caudal peduncle is long, and its depth enters the total length minus ` 
the caudal fin, thirteen times; its length enters the total minus the 
head, two and one-half times, Total length, 87 mm. ; approximate 
length of head, 29 mm. ; of caudal vertebre, 20 mm. Depth at ven- 
tral fins, 7mm. Elevation of dorsal fin, 7 mm. 
