I >i
1. T e t r o d o n AEROSTATICUS. Jen.
T . capite, doi'so, lateribus, et pinnâ caudali, nigro-maculatis ; ventre turgidissimo,
fasciis obliquis nigris : corpore undique nutricato, caudâ solum excepta : capite
brevi ; fro n te inter ocidos paululum depresso : m axillis oequalibus : lineâ latex'ali
nullâ: pinnâ dorsali onmino ante analem posità : pinn â caudali subrotundatâ.
D. 11 ; A. 1 0 ; C. 10 ; P. 11.
L o n g . u n e. 2. lin . 6.
F orm.— H ead short. Body approaching to globular, with the skin of the belly extremely loose and
capable of great inflation ; every where beset with m inute prickly asperities, the extreme end
of the tail alone excepted. Crown nearly flat, very slightly depressed between the eyes.
Jaw s equally advanced. Nostrils tubular. N o appearance of any lateral line. Dorsal entirely
in advance of the anal : both these fins small. Caudal slightly rounded.
C o lo u r .— {In spirits.) Head, back, and sides to the depth of the pectorals, greyish brown, spotted
w ith black ; the spots very small and crowded on the back, but becoming larger on the flanks
and tail. Belly white, with deep black oblique broad bands, inosculating in some places, so as
to form large meshes. Dorsal, anal, and pectorals, plain ; but the caudal very elegantly and
distinctly spotted.
The ticket attached to this specimen has been lost, and its locality is in consequence
unknown. In general appearance, it very much resembles the T . lineatus
of Bloch, of which it may possibly be a variety ; but it would seem to differ from
that species, in having the forehead less elevated ; in wanting the lateral line
altogether, of which I can discover no trace ; and in having the whole back and
upper part of the sides spotted, and not merely the tail and its fin, as is represented
in the T . lineatus.
2. TETRODON IMPLUTUS. Jen.
T . sordidè melallico-olivaceus, maculis circularibus albis ; venire albo, lineis olivaceis
longitudinalibus, haud admodum turgido : corpore suboblongo, magnâ ex parte Icevis-
simo, ventre solum muricato : m axillis suboequalibus : naribus tubulosis, bifurcatis :
lineâ laterali distinctâ,parum lortuosâ : pinnâ dorsali anali paulo anteriore : pinnâ
caudali oequali.
D. 10; A. 10 ; C. n ; P. 16.
L ong. unc. 4. lin. 9.
F orm.—Approaching to oblong, the belly a little ventricose. Head not so short as in the last
species, nor yet much produced. Body every where smooth, excepting the middle of the
abdomen from beneath the pectorals to the vent, and not very prickly here. Top of the head
slightly depressed between the eyes. Jaw s nearly equal ; the upper one, if any thing, a very
little in advance. Nostrils tubular, the tubes forked from the bottom into two equal branches.
The lateral line, which is very distinct, commences behind the mouth, whence it passes under
and partly encircles the eye, then arches upwards, making a long sweep, and not descending
till it gets above the anal, whence it proceeds nearly along the middle towards the caudal, but
loses itself before attaining to that fin. Dorsal fin rather in advance of the anal. Caudal
square.
C o l o u r .— “ D irty metallic olive-green, with white circular spots; belly white, with streaks of the
same colour as tho back.”— D . The spots extend on to the basal half o f the caudal, but are
smaller here than on tho body. A white annnlus encircles each eye, and a similar one is
described round the base of each pectoral. T he abdominal streaks run very exactly parallel
with the axis of the body, not obliquely as in the last species.
H abitat, Keeling Islands, Indian Ocean.
I can find no species noticed by authors exactly corresponding with the one
described above, which was obtained by Mr. Darwin at the Keeling Islands.
The form is similar to that of the llonckenii of KUppell,* but the colours
appear different. On the other hand, the markings resemble those of the T . tes-
tudinens of Bloch, but that species is rough all over.
3 . T e t h o d o n a n n d l a t u s . Jen.
T . dorso et laterihus nigro-fuscis, mmulis circularihus atris ; infra niveus : corpore
oblongo, haud admodum ventricoso, ubique sed pareé muricato, rostro et cauda
exceptis : capite grandiusculo, spatio interoculari lato, parum depresso : maxillis
suboequalibus : naribus cplindraceis, recumbentibus, aperturis duabus lateralibus :
lined laterali in capite tortuosissimâ : pinnA dorsali vix anali anterierre : pinnd caudali
D. 8 ; A. 7; C. 9, &c. ; P. 15.
L o n g . unc. 9.
F o rm .— O blong: head rather larg e; the snout a little more produced than in the last species.
Moderately ventricose, and apparently capable of a certain degree of inflation. N o where
perfectly smooth, except on the snout, tail, and here and there on the flanks; nor very rough,
tho prickles being m inute and rather scattered, most apparent on the back, nape, (whence they
advance to quite between the eyes,) and the middle of the abdomen. ^ T he interocular space is
broad, equalling two and a half diameters of the eye at least, and a little hollowed out. Jaw s
nearly equal, the upper one perhaps a very little in advance. Nostril in the form of a small
recumbent cylinder, with an opening at each extremity. Dorsal very little in advance of the
anal; the first ray in each of these fins very short. C audal square.
T he lateral line is very tortuous, especially about the head. I t commences at the bottom
of the gill-cover, whence it ascends vertically behind the eye towards the crown, then passes
over the eye towards the snout, descends again beneath the nostril to form a great loop in front
of the eye, almost reaching to the corners of the mouth, whence it returns beneath the eye,
* Surely this cannot bo the same as the T. Ifonckenii of Bloch?