1865.] MR.J.¥.JOHNSON ON A NEW TRICHIUROID FISH. 435 
maxillary. In front there are seven longer teeth, which are conico- 
compressed, and curve slightly backwards ; two of them at each side 
stand within the outer row of teeth. On the palatine bones there is 
a single row of minute teeth; whilst the vomer is unarmed. The 
tongue is also without teeth, and is black like the rest of the mouth 
and the inside of the gill-covers. A membrane with a tongue-like 
lobe stretches across the palate. 
The diameter of the round lateral eye is contained in the head 
about five times, and is distant from the muzzle 1% of its diameter. 
Near the angle of the preopercle are three very small flat teeth. The 
opercle terminates in two obtuse projections separated by a notch. 
The first dorsal fin commences a little in front of the root of the 
pectoral fin. Its height is rather more than half the height of the 
body ; and its length is less than half that of the fish. It rises out 
of a groove, and is supported by twenty-one slender spines, which 
are not tuberculated. The second dorsal fin commences shortly behind 
the termination of the first, to which it is not quite equal in point of 
height, and it is less than half as long. It is supported by nineteen 
rays, of which the first one or two are short; and it is followed by 
two longish finlets. The pectoral fin is inserted under the angle of 
the opercle ; it contains thirteen rays, and equals in length the second 
dorsal fin. The pair of spines representing the ventral fins are in- 
serted close together under the hinder part of the roots of the pec- 
toral fins. Their length is about a fourth of the height of the body; 
and, being longitudinally grooved, each appears to consist of two or 
three spines fused together. The vent is a little behind the middle 
of the fish. Behind the vent there is a flat dagger-shaped spine, 
which is longitudinally grooved. Its length is less than half the 
greatest height of the body ; but it is rather longer than the ventral 
spines. The anal fin commences about the length of the spine behind 
it, and is opposite to, but rather shorter than, the second dorsal fin. 
It contains eighteen rays, and is followed by two finlets, the second 
of which is elongated. The deeply forked caudal fin contains six- 
teen rays, with five or six short exterior rays on each side. 
The lateral line falls obliquely from its commencement above the 
opercle to the middle of the length of the fish, and is then continued 
with a gentler obliquity along the posterior part of the body to the 
tail, where it has two-thirds of the height above it. 
The single specimen of this fish which has occurred was obtained 
in the month of December, and it has been deposited in the British 
Museum. The fish bears a close external resemblance to the 
“Coelho” of Madeira (Thyrsites prometheus, Gthr. ; Prometheus 
atlanticus, Lowe). From that fish it may be distinguished by the 
possession of a dagger-shaped spine in front of the anal fin*, by the 
spines of the first dorsal fin being twenty-one in place of eighteen, 
by the rays of the second dorsal fin being nineteen in place of twenty- 
one, and by the rays of the anal fin being eighteen in place of six- 
* Aphanopus carbo, Lowe, and Nesiarchus nasutus, a fish described by me in 
the Society’s ‘ Proceedings’ for 1862, p. 173, pl. xx1t., have a similar spine be- 
tween the vent and the anal fin. 
