1878,] 679 loans, 
though generally present. The naked inferior surface of the scapular arch 
distinguishes this genus from Doras, and I now think that the peculiar 
form of the prefrontal bone has a similar value. The superior and anterior 
borders of the latter are free and pectinate as in Physopyzis. 
The Doras pectinifrons m. presents the same character, but the scapu- 
lar arch is covered below by thick skin as in Doras. I therefore regard it 
as representing a genus between the latter and Zathoraz, which may be 
called Agamyais. Doras grypus m. belongs to Doras. 
23. HYPOPTOPOMA BILOBATUM Cope, Proceed Amer. Philos. Soc. 1870, p. 
566, 
Coll. of 1878. 
26. HYPOPTOPOMA GULARE, sp. nov. 
This species is more robust than the H. bilobutwm, and differs in various 
respects. There are but 21 shields crossed by the middle line of the side 
instead of 25; the space between the sub-orbital bones and the clavicle is 
filled with an osseous shield wanting in H. bilobatum, and there is no me- 
dian series of abdominal scuta. As compared with the HA. thoracatwm 
Ginth, this fish exhibits similar proportions, having the head wider in 
proportion to the length than in H. délobatum. But the scuta of the throat 
and thorax in H. thoracatum are as in H. bilobatum, as well as the number 
of scuta crossing the lateral line. The caudal fin has the lobes sub-equal as 
in Z. bilobatum. 
Radii D. I. 7; A. I. 5; V. I. 5; P. I. 6. Pectoral spine reach- 
ing end of ventral spine; dorsal spine not branched at extremity, rather 
stout, nearly as long as the pectoral, its base 4 mm. nearer end of muzzle 
than base of caudal fin. Head very flat, quite wide, its width behind orbits 
about one-fourth the length to the base of the caudal fin ; its length to the 
superior angle of the gill opening, 3.8 times into the same. The spine sup- 
porting the adipose fin, stands on the anterior border of the fourth dorso- 
lateral scute counting from the base of the first superior caudal fulcrum. 
Some scuta between this point and the last dorsal ray. Each border of the 
muzzle supports a wide band of segments, within which a narrower band 
of segments bounds the median wedge-shaped area on each side. Inferior 
border of end of muzzle prickly ; eye with some inferior range. Scuta of 
head above, and those below as far as vent, finely granular; the others 
smooth. Color olive brown, each scute of the body, and the three nuchal 
ones with a pale border within the edge. Caudal with the rays brown, 
except a wide margin, and a vertical line beyond base, which are pale. The 
dorsal fin is deep brown at the base, and has some dark spots on its middle. 
Length M. .105; to base of pectoral fin .028 ; to base of anal .052; eleva- 
tion of dorsal spine .021. 
Coll. of 1877. 
27. CHANOTHORAX BICARINATUS. Gen. et sp. nov. 
Char. Gen. Callichthyiform fishes with osseous dorsal and pectoral 
spines, a produced occipital shield, and 9-11 soft rays in the dorsal fin. 
