168 MR. J. ¥. JOHNSON ON NEW GENERA AND SPECIES [June 10, 
“front. The vent is in the hinder half of the body, and about zath 
of the total length behind the middle. The anal fin commences 
within a short distance of the vent ; it is very low in front, where it 
is cloaked by thick skin, and where there is a furrow at each side of 
and parallel with its base; further behind there are two parallel 
furrows. The tail is compressed, the fin narrow and rounded. All 
the fins are covered with a thick skin. 
Although several specimens of this Eel have been obtained (some 
of which have been sent to the British Museum), it must still be con- 
sidered as a rare fish. In colouring it resembles Thyrsoidea unicolor, 
Kaup, from which it differs generically in the uniserial dentition. 
The following measurements were taken from a specimen having 
a total length of 40} inches, with a depth, near the gill-openings, of 
34 inches :— 
Inches 
Rietas: ear cite hahaa altos eee 254 
Gill-openings, distance from snout.......... 
Vent, distance from snout ................ 222 
Dorsal fin, distance from snout ............ 4 
In another specimen, 363 inches long, the longer axis of the eye 
measured 5%, inch, and the longest teeth were less than +th of an 
inch in length. The rictus was 15%; inch in depth. 
THYRSOIDEA ATLANTICA, Sp. n. 
Anguilliform, compressed; attenuate both ways from middle of 
body. Skin smooth, scaleless, white, with one dusky oval blotch on 
one side of body, and two or three such blotches on the other side, 
unsymmetrically placed. The longer axis of these blotches is from 
one-third to one-half an inch across. On the fins near the posterior 
extremity of the body are several similar blotches. 
A single specimen of this Eel has occurred, the dimensions of 
which are embodied in this description. 
Total length 23 inches; depth 1,4, inch, taken about an inch in 
advance of the vent. 
Head compressed, rising behind the eyes; depth through head 
and swollen throat, 1,4, inch. Eyes covered with skin, placed a little 
in advance of the middle of the upper jaw, rather less than one-fifth 
of an inch in diameter. Hinder nostril-tubes shorter than anterior, 
placed a little in front of the vertical from the anterior orbit of eye. 
Front nostril-tubes reaching a little beyond lip. Mouth cleft rather 
more than an inch deep. Jaws rather slender, somewhat curved, 
and not capable of shutting closely on account of the length of the 
front teeth and the curvature of the jaws. Lower jaw a little longer 
than the upper, without a barbel. Teeth in both jaws slender, 
pointed, somewhat compressed, curving backwards. In the upper 
jaw there are two rows at each side, those of the inner row being 
longer. A row of seven teeth along the middle of the palate. The 
longest teeth in the jaw are rather more than one-fifth of an inch in 
length. In the lower jaw there is a single row at each side ; in front 
