] 
28() REPORT OF COMMISSIONER OF FISH AND FISHERIES. [56] | 
aa. [Dorsal rays, 124; anal rays, 100; scales of blind side scarcely ctenoid, 30-105-32; 
snout and lips not scaly; maxillary 3 in head; eyes, large, 2? in head, separated by 
a very narrow ridge; head 4} inlength; depth about 3; light brownish gray, the 
fins dusky, the pectoral black.] (Goode § Bean) ...-.---..-----.----ATRIMANA, 65. 
64. MONOLENE SESSILICAUDA. 
Monolene sessilicauda Goode, Proc. U. S. Nat Mus., 1880, pp. 337, 338 (deep sea south 
of New England). Goode, Proc. U. S. Nat. Mus., 1830, 472 (deep sea south- 
ern coast of New England, stations 870, 871, 876, 877). Jordan & Gilbert, 
Syn. Fish. N. A., 1882, p. 841. Goode and Bean, Bull. Mus. of Comp. Zvol- 
ogy, Xix, p. 194 (station 314; South Carolina). 
Habitat.—Deep waters of the Gulf Stream. 
This species is known to us from the accounts of Goode & Bean. 
65. MONOLENE ATRIMANA. 
Monolene atrimana Goode & Bean, Bull. Mus. Comp. Zool., xii, 155, 1886 (deep | 
waters off Barbadoes). 
Habitat.—Deep waters of the Caribbean Sea. 
This species is known to us from the original description. 
Genus XX V.—ONCOPTERUS. 
Oncopterus Steindachner, Ueber eine neue Gattung und Art aus der Familie der 
Pleuronectoiden, 1874, 1 (darwini). 
TyPE: Oncopterus darwint Steindachner. 
This singular genus is based on a single species found on the shores of 
East Patagonia. It has no near allies among the American flounders, but 
it has several points of resemblance to the genera Rhombosolea, Ammotre- 
tis, and Peltorhamphus of the Australian fauna, and we have ventured to 
associate the four ina subfamily, which may be called Oncopterine. The 
Oncopterine agree in having some sort of peculiar appendage on or near 
the snout, apparently connected with the firstinterspinal. They agree 
with the Platessine in the general form, the dextral portion of the eyes, 
and in the structure of the mouth. Their nearest ally in this group is 
Pleuronichthys. In the insertion of the ventrals, they agree with the 
Pleuronectine and with the genus Achirus of the Soleine. In both 
Peltorhamphus and Rhombosolea, the ventral is continuous with the anal 
as in Zeugopterus and Achirus, but in Oncopterus the two fins are sapa- 
rate. In Peltorhamphus and Rhombosolea, the bone connected with the 
the first interspinal extends forward as a sort of nose, meeting the chin 
(much as in Achiropsis and Apionichthys). In Oncopterus this bone is 
twisted to the blind side, and has a very peculiar position, described 
below. The scales are smooth and cycloid in Oncopterus and Rhombo- 
solea, ctenoid in Peltorhamphus. In Peltorhamphus and Oncopterus the 
left ventral is present. It is wanting in Rhombosolea. Ammotretis we 
have been unable to examiue. In Oncopterus the lateral line has an an- 
terior arch and many accessory branches. It is straight and simple in 
the other genera. In all the teeth are sharp, close set, in a band, and 
chiefly on the blind side. 
