DERMANYSSUS. 



[ 242 ] 



DESMIDIACE^. 



Fig. 166. 



Deparia prolifera. 



Sorus enclosed in the stalked indusium. 

 Magnified 25 diameters. 



(last) joint smallest ; labium acute ; mandi- 

 bles of the male chelate, external claw very 

 long ; of the female, ensiform ; anterior legs 

 longest ; coxae approximate. 



D. avium (PI. e.^fig. 24). Found in the 

 cages of tame singing birds and upon poul- 

 try. Body ovate-oblong, depressed, slightly 

 broader and sometimes emarginate pos- 

 teriorly. The sixth joint of the legs (c) is 

 the longest. Mouth forming a kind of 

 moveable head attached to the under part 

 of the anterior margin of the body ; it con- 

 sists of: 1, a triangular labium, pointed in 

 front, and with two palpi (fig. 24 a*), the 

 second joint largest, the fifth smallest and 

 accompanied by a large but short, moveable, 

 external seta ; and, 3, the two mandibles 

 (b, of female ; t of male). Red or reddish 

 brown. 



This species sometimes infests human 

 beings, producing a skin-disease, being de- 

 rived from fowls. 



D. vespertilionis. Found upon the mouse- 

 coloured bat ( V. vnurinus). Rostrum nearly 

 as long as the palpi, broad or oval at the 

 base, narrowed in front, cleft longitudinally 

 above, and containing the two long and 

 slender mandibles. 



D. pipistrelli. On the common bat ( V. 

 pipistrellus). 



D. hirundinis. In the nest of the swal- 

 low. 



D. gallinee. On the common fowl. 



D. Nitzsckii. In the nostrils of the goat- 

 sucker (Caprimulffus). 



Other species are found on the noctule 

 bat ( V. noctuld), the merlin, the turkey, the 

 snail, the mouse, serpents, &c. ; and two on 

 the paeony and the convolvulus. 



BIB:L. I)ng&, Ann. Sc. Nat. 2 se"r. ii. 19 ; 



Gervais, Walckenaer's Arach. iii. 222 ; Busk, 

 Mic. Jn. 1842, ii. 65 ; Kolenati, Sits. Ak. 

 Wien, 1859, 172 ; Murray, EC. Ent. 169 ; 

 Me-gnin, Paras. 1880, 115. 



DERMATIS'CUM, Nyl. A genus of 

 Lichens, tribe Lecanorei, formed to con- 

 tain Endocarpon Thunbergii, a native of the 

 Cape of Good Hope. 



BIBL. Nylander, Enum. Gen. 116. 



DERM ATODEC'TES = SARCOPTES. 



DERMES'TES, Linn. A genus of Der- 

 mestidae. 



DERMES'TEm A family of Coleo- 

 pterous Insects. 



The larvae of these insects, which are 

 often minute, create great ravages amongst 

 dried skins, furs, &c. ; they also feed upon 

 feathers, bacon, books, paper, insects in 

 cabinets, mummies, &c. They are particu- 

 larly interesting to the microscopist, on ac- 

 count of the peculiar and beautiful structure 

 of certain of the hairs (PI. 1. fig. 1, a, 6) 

 existing unon their bodies. 



The hairs form three distinct tufts on 

 each side of the hinder segments of the 

 bodies of the larvae. The ordinary finely 

 spinous hairs on the rest of the body are 

 shown in c. 



Although these hairs are generally called 

 the hairs of Dermestes, it so happens that 

 this genus is almost the only one in the 

 species of which the hairs do not exist. 



British gen. : Anthrenus, Attagenus, Me- 

 gatoma, Tiresias, Dermestes, and Trinodes. 



BLBL. Westwood, Introd. i. j Curtis, Br. 

 Insects, 682 ; Stephens, Manual, 142. 



DESMAREL'LA, Kent. A genus of 

 Infusoria. 



Char. Free, united laterally into rows ; 

 flagellum single, terminal, encircled at the 

 base by a collar. 2 species, 1 in fresh, the 

 the other in salt water ; length of bodies 

 *oVo". (Kent, Inf. 341.) 



DESMARES'TIA, Lamx. A genus of 

 Sporochnaceae (Fucoid Algae), consisting of 

 olive or brownish seaweeds, with repeatedly 

 pinnate, feathery fronds, from one to several 

 feet long, growing chiefly between tide- 

 marks or in deep water. The characters of 

 the reproductive structures have not yet been 

 made out, as the species rarely fruit on our 

 coast, although the plants are common. 



BIBL. Harvey, Mar. Alg. 23, pi. 5D; 

 Phyc. Brit. 49, 115; Greville. Alg. Brit. 

 pi. 5. figs. 1 to 6. 



DESMIDIA'CE^E (PI. 14). A family of 

 Conferyoid Algae, consisting entirely of mi- 

 croscopic flexible organisms inhabiting fresh 



