TRACIIEARLE. 



467 



THE FIRST FAMILY OF THE TRACHEAN ARACHNIDA,— 

 The Psetjdo-Scorpiones, — 



Has the thorax articulated, with the anterior segment largest, like a corselet ; the abdomen very 

 distinct, and annulated ; the palpi very large, in the shape of feet or claws ; eight legs in both 

 sexes, with two equal-sized ungues at the tip of the tarsi, — the two anterior, at the most, excepted; 

 two apparent chelicerse, terminated by two fingers ; and two maxillae, formed of the basal joint of 

 the palpi. All of these are terrestrial, and have the body oval or oblong. This family comprises only 

 two genera. 



Galeodes, Oliv. (Solpuga, Lichteijstein, Fabr.), having- two very large chelicerae, with vertical, strongly-toothed 

 fingers, one superior, fixed, and often furnished with a slender, elongated, pointed appendage* at its base, and the 



other moveable ; the palpi are large, projecting, and 

 in the shape of feet or antenna 1 , terminated by a 

 short, vesicular joint, without any terminal hook; 

 the two fore-legs have a similar shape, and are equally 

 unarmed, but smaller; the others are terminated by a 

 tarsus, the last joint of which has two small cushions, 

 and two long fingers, with a hook at their tips; five 

 scales are attached by a peduncle upon each hind leg, 

 disposed in a row upon the basal joints; two eyes are 

 placed close together upon an eminence in front of 

 the anterior thoracic segment, which represents a large head, supporting the mouth and two fore-legs. 



The body is oblong, generally soft, and clothed with long bristles ; the knob at the tip of the palpi incloses a 

 peculiar organ, which is only protruded when the animal is irritated ; the two fore-legs may be considered as a 

 second pair of palpi. I have discovered a large spiracle on each side of the body, between the first and second 

 legs, as well as a slit at the base of the belly. The abdomen is 9-jointed. For further details, see the description 

 of a species found in Spain, by Dufour (Annates Set. Pltysiq., torn. v. pi. 69). 



It is supposed that the ancients designated these Arachnida under the names of Phalangium, Solifuga, Tetra- 

 frnatha, &c. M. Poe discovered a species near Havannah, but the others are peculiar to the warn) and sandy 

 countries of the old world. They run with very great quickness, erect their heads when surprised, showing signs 

 of resistance, and are reputed venomous. Solpugafatalis, Latr. Bengal. Others are described in the mouograph 

 of Herbstin, and the voyages of Olivier and Pallas. 



[Other species are figured, with elaborate details, by Savigny, in the great work on Egypt ; and M. Lucas has 

 described and figured a species from Cuba (G. Cuba-), in Guerin's Magarin de Zoologie. Dr. Schomburgh has 

 also forwarded, this year, to the Entomological Society of London, a species, of small size, from Deinerara, which 

 he found in the nest of a species of Termes.] 



Chelifer, Geoff. (Obisium, Illiger), has the palpi elongated like arms, with a claw -like hand with two fingers; all 

 the legs are equal, and terminated by two ungues ; the eyes stand at the sides of the 

 thorax. These animals resemble small Scorpions deprived of tails. The body is 

 flattened, with the thorax nearly square, and having one or two eyes on each side. 

 They run quickly, and often sideways, like Crabs. The eggs are united in a mass. 

 The elder Hermann says that they carry them beneath the belly; and he also believes 

 that these Arachnida are able to spin. The younger Hermann and Leach divide 

 them into — 



Chelifer proper, having the first segment of the thorax divided in two by a trans- 

 verse impressed line ; a style at the tip of the moveable finger of the chelicera: ; it 

 has only two eyes. 



l'lml. caneroides, Linn., commonly called the Book Scorpion, is found in herba- 

 riums, old bunks, &c, where it feeds upon the minute insects which frequent BUCh situations. Scorpio cimicoidet, 

 Fabr. Lives under stones, the bark of trees, &c. 



Obtttum, Leach, has the thorax without division ; the chelicera- without a style. It has also four eyes. 

 See the monograph of Seorpionida of Leach (Zool. Miteell. vol, iii.), and Dalman'i memoir on Copal Insect', 

 where a species is described under the name of Eucarpus. [Some new species of this group are described and 

 figured by M. Theis, in Annalet des Sci. Xat., Sept. 1832]. 



Kit;. 34.— Chelifer (nciMui. 



THE SECOND FAMILY OF THE TRACHEAN ARACHNIDA,— 



The Pycnogonides, — 

 Has the thorax composed of four segments, occupying nearly the whole length of the body, terminated 

 at each extremity bj > tubular article, of which the anterior (which is larger, and cither simple or pro- 



1 In Ml believe this nppendigc ii peculiar to one »ex. 



II 11 J 



