50 MODERN CLASSIFICATION OF INSECTS. 
the tribe Megaloptera (Latr., Nouv. Dict. d’ Hist. Nat. Tabl. Meéth.). 
They are distinguished by the larger size of the quadrate prothorax ; 
the palpi are short and filiform, the last joint not being larger than 
the preceding ; the head of moderate size (fig. 64. 11.) ; the labrum 
is cleft in the centre (fig. 64. 12.); the jaws horny, with a single 
sharp apical tooth (fig. 64. 13.); the maxille are terminated by two 
minute lobes; the maxillary palpi in Sialis are 4-jointed (fig. 64. 14.) ; 
the labium is large, with reflexed 3-jointed labial palpi, the true labium 
(ligula) not extending beyond the palpi, but internally dilated (jig. 
64,15.) ; the anterior wings are of large size, either deflexed at the sides 
(Sialis), or carried nearly horizontally (Corydalis, &c.), the posterior 
pair are rather smaller than the anterior ; the antenne are long, fili- 
form, and multi-articulate ; and the tarsi are 5-jointed, either with the 
joints simple, or with the fourth joint lobed beneath (Sialis, fig. 64. 16.) 
The ocelli are absent in Sialis, but they exist of a large size in Corydalis. 
These insects are very slow and inactive in their movements; 
they frequent the neighbourhood of water, in which they pass the 
larva state. The ordinary species (Sialis lutaria Zinmn.), is a well- 
known bait with the angler, being produced in the spring months in 
great quantities. It is of a dull brown colour, and may be found upon 
walls or palings near the water. The female deposits an immense 
quantity of eggs, which she attaches one by one to rushes or other 
aquatic plants; they are of a cylindrical form, terminating at the top 
in a sudden point ; they are attached together side by side with the 
greatest regularity ( fig.64.17.). ‘The larva (fig. 64. 18.) inhabits the 
water, in which it swims well by the assistance of seven (Latreille, 
De Geer, and my specimens, or eight, according to Pictet) pairs 
of slender 4- (5- ?) articulated setose filaments, attached at the sides 
of the abdominal segments, representing the false gills of the larvae of 
Ephemeride, with which they are evidently analogous in their respir- 
atory action.* The abdomen is terminated by a long and slender 

Gray, in Griffith An. Kingd., pl. 72. 
De Geer. Mémoires, tom. iii. tab. 27. 
Palisot Beauvois. Neuropt., pl. 1. 
Drury. Exotic Entomology, vol. i, pl. 46. 
Newman. Entomol. Mag., No. 25. 
* M. Pictet notices the curious fact, that one of these larve lived fifteen days in 
the earth before it changed toa pupa, being the only instance of an insect furnished 
with external respiratory organs respiring the ordinary atmospheric air. 
