SOLPUGID^E, PHALANGID^E, AND ACARIDJE. 38 5 



abdomen, with no deep constriction or separation be- 

 tween the thorax and abdomen ; eight unguiculated legs ; 

 and a tail of six joints, separated from each other by a 

 deep strangulation,, the last bearing a curved hook, 

 whereby the insect inflicts a wound and injects a poison. 

 These are terrific creatures, whose poison becomes the 

 more virulent as they approach the torrid zone. None, 

 fortunately, are natives of this country, but several occur 

 in the South of Europe. 



(348.) The Solpugidce, the first division of the 

 tracheal Arachnida, are equally hideous with the last 

 in aspect, being usually covered with long hairs or 

 spines ; and are said to be also venomous; but, if so, the 

 poison must be injected by the mandibles. They have 

 the head, thorax, and abdomen, separated by a strangula- 

 tion. They have eight legs, the anterior pair being pal- 

 piform, as are also their maxillse ; whilst their mandibles 

 form robust didactyle claws ; and their abdomen consists 

 of a succession of segments. They frequent hot coun- 

 tries and sandy districts, especially of the Old World. 

 They run with great rapidity, holding up their heads 

 as if to defend themselves. With these, doubtlessly, 

 Chelifer and Obisium may be united ; which are minute 

 animals, both natives of our own country, where they 

 frequently occur in moss. The second division consists 

 of the Phalangidce, in which the head, thorax, and abdo- 

 men are united, and the latter not divided into segments, 

 but by its epidermis being frequently folded, it thus 

 resembles a segmental division. Their mandibles are 

 very robust, and with didactyle claws, eight unguiculated 

 legs, and either slender and filiform or spinose palpi. 

 Their legs are usually exceedingly long and very slender. 

 Some occur in this country, but perhaps the most ec- 

 centric forms among them are found in Gonoleptes and 

 its affinities, from the Brazils. They usually occur run- 

 ning upon the ground or on plants, and are very active ; 

 some also are found under stones, or in moss. 



(349.) The last tribe of the Arachnidce are the Aca- 

 ridce. or mites. Head, thorax, and abdomen are here 



C G 



