S I R E X. 
animal has hitherto been found of which it can possibly be 
supposed the larva.” 
3. Siren pisciformis, or ferruginous-brown siren.—Spotted 
with black, with finely ramified branchiae, tetradactylous fore 
and pentadactylous hind-feet. This animal, in the Natu¬ 
ralist’s Miscellany, is denominated Gyrinus Mexicanus, or 
Mexican tadpole. According to the description given in 
that work, it is a native of Mexico, and, if only the larva of 
some large American lizard, is scarcely a less singular and 
curious animal than the siren. In its general appearance it 
bears some resemblance to the larva of the Rana paradoxa, 
but is furnished with gills, opening externally in the manner 
of a fish; the openings are very large, and the external flap 
is continued from the sides of the head across the throat be¬ 
neath, so as completely to insulate the head from the breast; 
the gills themselves consist of four semicircular bony or car¬ 
tilaginous arches, which are denticulated or serrated on their 
internal or concave part, like those of fishes; on the opercula, 
or external flaps, are situated three very large and elegant 
branchial fins, or ramified parts, divided and subdivided into 
a vast number of slender or capillary processes. In these 
particulars it resembles the siren lacertina, except that in the 
latter animal the external opening to the gills is very small; 
the mouth is furnished in front with a row of extremely mi¬ 
nute teeth; the tongue is large, smooth, and rounded at the 
tip; the rictus, or gape, when the mouth is closed, appears 
considerably wider than it really is, owing to a lateral sulcus 
proceeding from each corner to some distance; the feet are 
entirely destitute of webs, and they are furnished with rather 
weak claws; the front feet have four toes, and those behind 
five. Independently of the general colour of the animal, 
the whole skin, when minutely examined, appears to be scat¬ 
tered over with very minute white specks, resembling those 
on the surface of the siren lacertina. The sides of the body 
are marked by several strong rugae or furrows, and an im¬ 
pressed lateral line or sulcus is continued from the gills to the 
tail. 
Siren is also a name given by Mouffet, and other authors, 
to a species of bee; of which they distinguish two kinds, a 
larger and a smaller. These differ greatly from the common 
bee, in that they live solitary, and never unite into swarms, 
Or build nests, or make combs. 
To SI'RENIZE, v. n. To practise the allurements of a 
siren. Cockerham. 
SIREX, or tailed wasp, in Entomology, a genus of in¬ 
sects of the order hymenoptera, of which the Generic Cha- 
tacter is, mouth with a thick, horny, truncate, short, den¬ 
ticulate mandible; four feelers, the hind ones longer, and 
thicker upwards; antennse filiform, of more than twenty 
equal articulations; the sting is exserted, serrate and stiff'; 
the abdomen is sessile, terminating in a point; wings lan¬ 
ceolate, incumbent, the lower ones shorter. 
The larvae of this genus are six-footed, soft, cylindrical; 
the head rounded; they perforate whod, and frequently eat 
their way into the bowels of other insects, and their larvae, 
living upon them till they have utterly consumed their en¬ 
trails ; the pupa is folliculate; the perfect insect lives on the 
nectar of flowers. There are about twenty-six species, of 
which the most remarkable are: 
1. Sirex gigas.—The abdomen of this species is yellow’at 
the base and tip ; the body is black-blue. This is the largest 
species in the whole genus: it surpasses a hornet in size, and 
is principally observed in the neighbourhood of pines and 
other cone-bearing trees: it is of a black colour, with the 
eyes, the base, and lower half of the abdomen, of a bright 
orange-yellow ; the thorax is villose, and the wings of a 
transparent yellowish-brown ; the sting, or terminal tube, is 
very conspicuous. The larva, which measures about an inch 
and a quarter in length, is of a yellowish-white colour, and 
inhabits decayed firs and pines; at first view it bears some re¬ 
semblance to the larvae of the beetle tribe, but is thinner in 
proportion, and furnished, at the tip of the abdomen, with 
a short black spine or process. It changes to a chrysalis in 
the month of July ; first enveloping itself in a slight silken 
web of a whitish colour. The chrysalis is of a lengthened 
Vol. XXIII. No. 1568. 
249 
shape, with the antennse, legs and terminal tube or process, 
very distinctly characterized. If the change to chrysalis 
takes place, as it sometimes does, in summer, the fly pro¬ 
ceeds from it in the space of about three weeks; but if at 
the close of autumn, the animal continues a chrysalis the 
whole winter, emerging in the following spring. The male 
insect is considerably smaller than the female, and may be 
farther distinguished by the want of the caudal tube or pro¬ 
cess, so conspicuous in the female insect; the tip of the ab¬ 
domen is also of a black colour. The eggs, which are 
deposited by the female in the decayed parts of the trees al¬ 
ready mentioned, are very small, and of a lengthened oval 
shape, with pointed extremities. 
2. Sirex Psyllius.—-Abdomen yellow’ at the base and be¬ 
fore the tip; the body is black.—It inhabits different Euro¬ 
pean countries, and is half the size of the last. The antennae 
and legs are yellow, and the thighs black; the head is black, 
with a yellow spot on each side, behind the eyes; certain 
segments of the abdomen yellow. 
3. Sirex Columba.—This is an American species, and is 
distinguished by its black body, marked by testaceous bands. 
The Specific Character is as follow’s: thorax villous, ferru¬ 
ginous ; abdomen black, the sides are spotted with yellow; 
the antennse are short and black, ferruginous at the base; the 
abdomen beneath is black, with a yellow streak; the projec¬ 
tion is short, acute, serrate, yellow tipped with black ; the 
legs are yellow; hind-thighs black. 
4. Sirex magnus.—Black, thorax villous; tip of the antennae, 
lateral spots on the abdomen, shanks and base of the tarsi, are 
white. It is of the size of the Sirex gigas, and is found in 
many parts of Saxony. The abdomen beneath is white in 
the middle; the wings are dusky. 
5. Sirex nigricornis.—Thorax villous, blueish-black; 
abdomen ferruginous, blue at the base.—It is found in 
North America. The head is shining blue-black ; the an¬ 
tennse are black ; the legs are piceous; thighs yellow; sting 
pitchy. 
6 . Sirex flavicornis.—Thorax villous, black, immaculate; 
four bands on the abdomen, antennse and legs yellow.—It is 
found at Labrador, in America. The head is black ; the 
upper part of some of the segments is yellow; the appendage 
serrate, yellow; the sting is black. 
7. Sirex fuscicornis.—Thorax villous, black; abdomen 
with eight yellow bands; the antennse are black; the legs 
are yellow.—This, which is of the size of the gigas, inhabits 
Saxony. The wings are subtestaceous; the sting is black, 
with a yellow sheath; the horn of the abdomen is subulate, 
yellow, tipt with black ; the thighs are black. 
8 . Sirex spectrum.—The abdomen of this species is black; 
the thorax is villous, with a yellow stripe before the wings. 
It is found in this country, and in many other parts of Eu¬ 
rope. The antennae are black or yellow, and the legs are 
yellow. 
9. Sirex juvencus.—The abdomen is blueish-black; the 
thorax villous, immaculate.—This also is a native of England 
and other European countries. The antennae are black or 
yellow; the legs are yellow. 
10. Sirex phantoma.—Abdomen above yellow, with 
black belts; the head and legs are yellow.—It inhabits Ger¬ 
many. The mouth is black; the thorax yellowish before, 
beneath black ; the abdomen beneath is black. 
11. Sirex cyanus.—This is of a shining blue colour; the 
the legs are yellow.—It inhabits North America. The an¬ 
tennae are black ; the thorax sub-villous; the wings are hy¬ 
aline. 
12. Sirex albicorn is.—Black ; head with a white spot on 
each side; the antennae are white in the middle.—It is a 
native of North America. The antennae are black at the tip; 
the abdomen with a white dot on each side on the last seg¬ 
ment but one ; the legs are black ■ the shanks and ends ot 
the tarsi are white. 
13. Sirex nigrita.—This is of a black-blue, immaculate; 
the hind-legs are compressed.—It is a native of Saxony, 
and is of the same size as the sirex mariscus, hereafter to be 
noticed, 
3 S 
14. Sirex 
