CASS1D A. 



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birds, so that when they attack a field in numbers it 

 is very difficult to drive them off; and though their 

 temerity makes them easily killed by the gun, they 

 are not worth powder and shot on their own account; 

 for though sometimes eaten, they are far from being 

 palatable. Destructive as they are, however, it is 

 highly probable that they do the farmers upon the 

 whole more good than harm, from the incalculable 

 numbers of insects and larvae which they destroy ; 

 and which but for the birds would render many parts 

 of North America unproductive and uninhabitable. 



They are remarkably good-tempered birds, living 

 readily in confinement, and even, if at all attended to, 

 running about the house without any restraint, and 

 following those who feed them, with expressions of 

 fond recognition and regard. Their song is not one 

 of the finest, though tolerable, but they make up in 

 quantity, and their manners are exceedingly lively 

 and playful. 



Or YKHINCHUS. The distinguishing character of 

 this sub-genus is, the bill quite straight, but much 

 she ter than the head, whereas in the others it is as 

 lo-.g or longer. There is but one known species, 

 r'lnmiccps, which has a crest of long feathers mottled 

 with red. 



DACNIS. The birds of this sub-genus are very 

 small ; but in other respects they have the general 

 characteristics of the family. The bill is conical and 

 pointed. There are many species, but it will be suffi- 

 cient to mention one as a specimen. They have 

 sometimes been in part classed with the wagtails, 

 and in greater part with the warblers but they do 

 not belong to either. Their general colours are blue, 

 black, and yellow. The best known species is, De 

 Cayana, the Cayenne pit-pit, or Cayenne warbler. 

 General colour blue, with the nape, scapulars, wings, 

 and tail, black. Its colours, especially during the first 

 two years, are, however, subject to much variation, and 

 \t has been multiplied into several species. The birds 

 .nhabit the forests, where they are gregarious, and 

 perch in flocks on the tops of the highest trees. Most 

 of the others are similar both in size and in habits ; 

 / and it is not improbable that many of the described 

 species are the same birds in different states of their 

 plumage ; and also that there are many others in the 

 depths of the vast forests of Cayenne, Guiana, and 

 similar parts of South America, which have not yet 

 been discovered. To cross those forests is often no 

 easy matter, to explore them properly is impossible, 

 a thousand men occupied every day for a hundred 

 years would still leave much to be found out in the 

 highly interesting- natural history of those most pro- 

 ductive regions. 



CASSIDA (Linnaeus). The tortoise-beetles. A 

 very extensive genus of coleopterous insects belonging 

 to the section Tetramera, and sub-section Cycllca, 

 and forming the type of the tribe Cassidarice of 

 Latreille, which is distinguished by having the 

 antennae inserted on the upper surface of the head, 

 nearly together, straight, short, filiform, and cylindric, 

 or somewhat thickened toward the tip; the mouth is 

 placed entirely on the underside of the head, the 

 various parts being very short, but the mandibles are 

 broad and strong ; the legs are short with the tarsi 

 flattened, the third joint being deeply cleft, receiving 

 between its lobes the terminal joint. The bod}' 

 being flat beneath, enables the insects, with the assist- 

 ance of these flattened tarsi, to lay close to the leaves 

 upon which they are found, and where they often 



remain immoveable ; the form of the body is generally- 

 orbicular or oval, the head being often completely 

 concealed beneath the thorax, the margins of which, 

 as well as of the elytra, are greatly dilated, so as to 

 give the insects the appearance of small tortoises, 

 especially, as on being disturbed, they contract their 

 antennae and legs under the broad sides of the thorax 

 and elytra, so as completely to conceal them. These 

 insects are of very varied colours, which, especially 

 in the larger exotic species, are elegantly disposed 

 in spots, lines, bands, &c., upon grounds o"f diti'erent 

 colours. They are entirely herbivorous in their 

 habits. The genera are Alurnus, Hispu, Chalepus, 

 Imatidium, and Cassida. In the first of these are 

 contained the largest species of the tribe, being 

 chiefly inhabitants of South America; they are of an 

 oval form with the head uncovered. 



The genus cassida is distinguished by its orbicular 

 or nearly ovoid form, with thorax generally semicir- 

 cular, covering and concealing the head, and furnished, 

 as well as the elytra, with a broad dilated margin 

 extending far beyond the sides of the body, as may 

 be seen in our figure of Cassida viridis, the utider side 

 of which is represented. The mandibles are short 

 and strong with several teeth. Scarcely any of the 

 species exceed one inch in length ; but amongst the 

 exotic species many very remarkable forms are to be 

 observed : several Brazilian species are armed with 

 two erect spines on the centre of the elytra, which 

 meet together when these organs are closed, forming- 

 an acute and robust horn nearly half an inch long. 

 Some of the species are highly metallic, amongst 

 which are several British species ; the latter, however, 

 lose their beautiful colours when dead, but which 

 may be reproduced by dipping them into hot water. 



It is not, however, in the perfect state alone that 

 nature has furnished these insects with a shield-like 

 covering for their defence, since, in the earlier period 

 of their existence, they are provided with the means 

 of constructing a covering of the most singular nature. 

 Reaumur has given us very ample details of their 

 proceedings, and it is from his figures, corrected 

 from our own specimens, that our illustrations of this 

 genus have been derived. 



Cassida viridis ill its different states. 



The larva of the tortoise-beetles is rather broad, 

 rather narrowed behind, and of a flattened form, with 

 the sides of the body furnished with branched spines 

 or setae. The extremity of their bodies is also fur- 

 nished with two long and slender scaly appendages 

 terminating in a point, and which form a kind of fork, 

 which is generally recurved upon the back of the 

 larva ; the anal aperture is placed at the base of this 

 fork upon a fleshy tubercle, which the insect has the 

 power to raise or depress at will ; and the insect has 

 the extraordinary instinct by the assistance of this 

 apparatus to collect its excrement, which is pushed 

 forward and upwards, sliding along the fork, w hen it 

 has accumulated at its base, by means of the con- 



