CLASS IX. 
ARACHNIDS (ARACHNOIDEA). 
Tue Arachnids were counted by Linn aus, as was stated above 
(p. 248), to belong to the class of insects. They were first separated 
from these as a distinct class by LAMARcK (1801), who placed all 
the wingless insects of Linnaus, which undergo no transformation 
and breathe by air-slits, in his class of the Arachnida?. To this 
then the myriapods, spring-tails, and parasites, would also belong, 
which we have placed amongst the insects (pp. 288—303), and 
LAMARCK accordingly divides his Arachinida into those which 
have antennee, and those which are without these parts. It is the 
last alone, which we, following LATREILLE, refer to this class. 
The class of arachnids, thus limited, is a very well defined and 
natural division of the animal kingdom. The arachnids are arti- 
culate animals with articulate feet or legs (see pp. 33, 248) and 
without antenne. The head is with them joined to the thorax, so 
1 For this class we cite especially the following works: 
ALBIN Spiders. —ELEazar ALBIN, Natural History of Spiders, illustrated with 53 
plates. London, 1736, 4to. 
CLEeRCK Aran.—CaROLI CLERCK Aranei Succict descriptionibus et figuris eneis illus- 
tratt. Stockholmize, 1757, 4to. 
Murtier Hydrachn.—Hydrachne quas in aquis Danie palustribus detexit, descripsit, 
pingt et tabulis XI. eneis incidi curavit O. F. Murntumr. Lipsie, 1781, 4to. 
Herm. Mém. apt.—Mémoire apterologique par J. F. HERMANN. Avec g Pl. enlum. 
Strasbourg, 1804, fol. 
WALCKEN. Aranéid.—Histoire naturel des Aranéides par C. A. WALCKENAER. 
Paris et Strasbourg, 1806. (5 parts in 12mo, with col. fig. in the taste of PANZER 
Deutschl. Ins.) 
SunDEV. Conspect.—C. J. SUNDEVALL Conspectus Arachnidwm. Londini Gothorum, 
1833, 8vo. 
Hann u. Kocu Arachn.—C. W. Hann Die Arachniden, getrew nach der Natur 
abgebildet u. beschrieben. 1, 2. 8vo. Niirnberg, 1831—1835; C. J. Kocu Die Arach- 
niden (continuation of Hann’s work). Niirnberg, 1836—1846. 3—12 vols. 
Kocu Deutschland’s Arachniden, in HERRICH-SCH&FFER’S continuation of PANZER’S 
Deutschl. Ins. (Acari). 
Kocu Uebersicht.—C. J. Koon Uebersicht der Arachniden-Systems. Niirnberg, 1837 
—1847 (4 parts with plates). 
WALCKEN. et Gerv.—WHistoire naturelle des Insectes aptéres. 4 vol. Paris, 1837— 
1848. (Suites & Burron chez Roret; the first three parts; the third is by GERVAIS.) 
2 Systéme des Animawe sans vert. p. 171. 
