750 



MALLOPHAGA AND ANOPLURA [LICE) 



species. This condition of life, wtiich is exactly similar for many different 

 species, is suitable for the production of many varieties of one and the same 

 species, and hence the description of a given species has to be of a very flexible 

 character, but it is opposed to the production of those more distinctive 

 differences which are utilized to make genera and families. 



Hence, although in these orders the varieties and species may be many, 

 the genera and families are but few in number. Thus, for example, in the 

 Mallophaga there are about 1,500 known species grouped into 27 genera, 

 4 families, and 2 suborders. 



The important difference between the Mallophaga and tho 

 Anoplura is that the former have a masticatory mouth, while the 

 latter have a sucking mouth. 



ORDER MALLOPHAGA Nitzsch, 1818. 

 Synonyms. — Mandibulata De Geer, 1783; Ricinidce. 



Nomenclature.^ — The name Mallophaga is derived from /xaXXos, wool, and 

 (payeiu, to eat. 



Definition. — Hexapoda usually of small size, wingless, provided with 

 biting mouth parts and with simple incomplete metamorphosis. Habitat, 

 epizoic parasites on birds and mammals. 



Historical. — The first descriptions and illustrations of these animals are 

 to be found in Redi's ' Esperienze intorno alia Generazione degl' Insetti,' 

 published in Florence in 1668, where the illustration on Plate 2, called ' Pollino 

 de Piccion Grosso,' is the same as Linnaeus' Pediculns columhcs, or pigeon 

 louse, and Nitzsch's Lipurus baculus, a name by which it is still known; while 

 the figure termed ' Pollino dell' Arzavola o Forquetola ' on Plate 12 is the same 

 as Nitzsch's Trinoton luridum, the duck louse. Linneeus classified all these 

 bird lice under the generic term of ' Pediculus,' from which they were 

 separated by De Geer, in 1783, under the term ' Ricinus,' because their masti- 

 catory mouth, enabling them to eat pieces of skin, hairs, and feathers, distin- 

 guished them from the blood-sucking species, for which the name ' Pediculus ' 

 was retained. 



The name ' Ricinus ' was changed into ' Nirmus ' by Hermann in 1804, 

 while the whole of the species known at the time were classified and named 

 by Nitzsch in 181 8, since which date our knowledge of these parasites has been 

 increased by Denny in 1842, Giebel in 1874, Piaget in 1880 and 1885, Taschen- 

 berg in 1882, Kellogg in 1908, 191 3, and 1914, as well as by many other 

 observers whose papers may be found in the Bulletin of Entomological Research 

 and in the Annals and Magazine of Natural History. To all these works the 

 reader is referred for a fuller knowledge of these interesting parasites than that 

 which can be given in the present work. 



Morphology. — The Mallophaga vary in size from i'5 to 10 mm., and from 

 1-2 mm. in breadth, but the majority are small, about 2*5 millimetres in length. 

 The body is strongly chitinized, smooth, wingless, and flattenened dorso- 

 ventrally. The mouth parts are of the biting type, with well- developed 

 mandibles, and in some species the labial palps are easily seen. The eyes 

 are represented by a single pair of ocelli placed at the lateral margins of the 

 head. The antennae are 3-5 segmented, and may be concealed in a groove, 

 or the ventral aspect of the cheeks, or may be exposed. 



The prothorax is distinct, but the meso- and meta-thoraces are sometimes 

 united, and may also be with difficulty differentiated from the abdominal 

 segments. The legs are flattened, long, and strong, and end in one or two 

 claws. 



The body varies in colour, being whitish, pale brownish, or dark brown in 

 colour, and marked by darker spots and bands, which are caused by chitiniza- 

 tion. 



The pharyngeal sclerite may be present or absent, as may be the accompany- 

 ing glands ; the crop may be simple or have a sac-like diverticulum. Ingluvial 



