Orders. SUCTORIA. 489 



founded with the abdomen, and the four hind legs very robust. (See Dr. Alibert's fine work upon the maladies 

 of the skin.) 



Other species, found upon different quadrupeds, have been figured by Redi, but in a coarse manner. Tliat which 

 Jives upon the Pig has the thorax very narrow, with the abdomen very broad (Pediculus Suis, Linn., forming Leach's 

 genus Hcematopinits). The Louse of the Buffalo, figured by De Geer (Ins. vol. vii. pi. 1, f. 12), is more singular. 

 (Pediculus Cervi, Panzer, belongs to the dipterous genus Melophagus.) 



The other species {Nirmidea, Leach), such as Ricinus, De Geer, Nirmus, Herm. & Leach, have the 

 mouth on the under side of the head, and composed, on the outside, of two lips, and of two hooks and 

 manchbles. The tarsi are verj' distinct, articulated, and terminated by two equal nails. 



With the exception of a single species, that of the Dog, all the rest are found exclusively upon birds. 

 The head is generally large, sometimes triangular, or in the others in the form of a semicircle or crescent, 

 and has often angular projections. It differs sometimes in both sexes, as well as the antennae. I have 



§ perceived, in many species, two simple eyes close together, on each side of the head. 

 According to observations communicated to me by M. Savigny, these insects have 

 maxillae, with a very small palpus upon each, hidden by the lower lip, which has also 

 similar organs. They have, also, a kind of tongue. 

 M. Leclerc de Laval has stated to me that he discovered, in their stomach, morsels 

 of the feathers of birds, which he believes is their only food. De Geer asserts, never- 

 theless, that he found the stomach of the Ricinus of the Chaffinch filled with blood, 

 Fig. 50.— Ricinua ^'i*^ wMch it had gorged itself. It is also known that these insects can subsist hut a 

 Pavonis. ^gj^ short time upon dead birds. They are then observed crawling, with uneasiness, 

 upon the feathers, particularly upon those of the head, and near the beak. Redi has figured a great 

 number of species, [as has also Lyounet, in his posthumous memoirs]. 



Some species have the mouth situated near the anterior extremity of the head ; the antennae are inserted at the 

 side, at a distance from the eyes, and are very small. PedicuUs Sterna:, Hirundinis, Liun., &c. 



In the other species, the mouth is nearly central ; the antennae placed very near the eyes, and their length is 

 nearly equal to that of half the head. Ricinus Gallime, De Geer, &c. 



A celebrated German naturalist, Dr. Nitzsch, deeply studied the internal and external anatomy of these animals, 

 of which he published a memoir in Germar^s Magazine. The true genus Pediculus, or the species provided with a 

 suctorial mouth, is arranged by him w ith the Epizoical Hemiptera. The genus Ricinus, De Geer (Nirmus, Herm.), 

 or the species provided with mandibles and maxiUae, are referred to the order Orthoptera, and collectively named 

 Mallophaga. Two genera of the latter are allied to the former, in being found upon various Mammalia. They are 

 Trichodecles, having the maxillary palpi obsolete, and living upon the Dog, Badger, &c. ; and Gyropus, having 

 distinct maxillary palpi, and living upon the Guinea-pig. The last-named genus has the mandibles entire, and the 

 labial palpi obsolete, thus differing from Liotheum, which has the mandibles bidentate, the labial palpi distinct, 

 and the tarsi terminated by two nails. The species are found on various birds, as are also those of the last genus, 

 Philopterus, which have 5-jointed antennae, the third often branched in the males, and the maxillary palpi are in- 

 distinct. We have not space to enumerate the subgenera into which Nitzsch has divided these genera, in all of 

 which the pro- and mesothorax compose the trunk, the metathorax being soldered to the abdomen. The subgenus 

 Goniodes is restricted to the gallinaceous birds. AVe have described a species of Philopterus in detail, in the col- 

 lection of memoirs at the end of our History of Ants. 



M. L. Dufour has formed a new genus (TrionguUmis) for the Pediculus Melitta of Kirby, previously obsen'ed by 

 De Geer, who regarded it as the lar\-a of Metoe proscarabaus. If it be not the larva of this insect, as Kirby sup- 

 posed, doubtless it would form a distinct subgenus in the order Parasita ; but Messrs. Serville and Saint Fargeau 

 have confirmed De Geer's statement, [as it has also been by numerous recent English observers, as Doubleday, 

 Newport, Newman, Jenyns, &c.] 



[In addition to the species figured by Redi, De Geer, and Lyonnet, and those indicated (from the species of ani- 

 mals attacked), but not specifically described, by Nitzsch, various species have been described by L. Dufour in the 

 Annates de la Societe Entomologique de France ; and by J. G. Children, Esq., in the Appendix to Captain Back's 

 Voyage to the North Pole. Mr. Denny has also announced an illustrated monograph of the order.] 



THE FOURTH ORDER OF INSECTS,— 



SUCTORIA, De Geer, (SiPHONAPTEKA, Latr., [Aptera, M'Leay ; Aphaniptera, KirbyJ),— 



Terminates the Apterous Insects, and has the mouth formed of a sucker of three * pieces, in- 

 closed between the articulated plates, forming together a rostrum or beak, either cylindrical 



* RoRsel only represents two, but Kirby and Strauss have observed one more. According to the latter, the scales covering the base of the 

 beab are the palpi. 



