866 THE ARACHNOIDAE. $ 295. 
ORDER III. 
Abdomen and cephalothorax unarticulated, distinct. from each other. 
Respiratory organs consisting of tracheae and lungs. 
SUB-ORDER VII. ARANEAE. 
Genera: Mygale, Thomisus, Uptiotes, Lycosa, Dolomedes, Salticus, Seges- 
tria, Dysdera, Scytodes, Clubiona, Drassus, Agyroneta, Clotho, 
Agelena, Lachesis, Tegenaria, Micryphantes, Theridion, Linyphia, 
Epeira, Tetragnathus. 
ORDER IV. 
Abdomen articulated. Cephalothorax unarticulated. Respiratory or- 
gans consisting only of lungs. 
SUB-ORDER VIII. PHRYNIDAE. 
Abdomen distinct from the cephalothorax. Cheliceres unguiculate. 
Genera: Thelyphonus, Phrynus. 
SUB-ORDER IX. SCORPIONIDAE. 
Abdomen indistinctly separated from the cephalothorax. Cheliceres 
forficulate. 
Genera: Scorpio, Buthus, Androctonus. 
BIBLIOGRAPHY. 
Leeuwenhoek. Continuatio arcanorum naturae, 1719, Epist. 138, p. 
312. 
Roesel. Insekten-Belustigungen, Thl. IV. 1761, p.-241. 
Degeer. Abhandlungen zur Geschichte der Insekten, VII. 1783. 
Hermann. Mémoire aptérologique, 1804. 
J. F. Meckel. Beitrage zur vergleichenden Anatomie, I. Hft. 2, 1809, 
. 105. ; 
: Treviranus. Ueber den inneren Bau der Arachniden, 1812. Ver- 
mischte Schrift. anat. u. physiol. Inhalts. I. 1816. Ueber d. Bau d. Nigua 
(Acarus americanus), in his Zeitsch. f. Physiol. IV. 1831, p. 185, 
Serres. Mémoires du Mus. d’hist. Nat. V. 1819, p. 86. 
Léon Dufour. Ann. génér. d. Se. physiq. d. Bruxelles, [V.—VI. 
J. Miller. Beitrage zur Anatomie des Scorpions, in Meckel’s Arch. f. 
Anat. 1828, p. 29. 
Lyonet. Anat. de différentes espéc. d’Insectes, in the Mém. du Mus, 
Whist. Nat. XVIII. 1829, p. 282, 377. 
Brandt. Medizin. Zool. IT. 1833, p. 87. Recherch. sur Vanat. d. Araig- 
nées, in the Ann. d. Se. Nat, XIIT. 1840, p. 180. 
Savigny. Descript. de "Egypte. Hist. Nat. Arachnides, Pl. I-IX. 
Audouin. Lettre contenant des recherches sur quelques Araignées 
