>' oBPlON'ES. •' 



of cephalothoracic limbs ; coxae 



of posterior four thoracic limbs 



in contact. 

 a' . Carapace distinctly segmented; 

 mandible articulated to the eidee 

 of its anterior plate ; append- 

 ages of 2nd pair leg-like and 



tactile. Of large size SOLIFUGM 



b\ Carapace not segmented, merely 

 transversely grooved : man- 



JO 7 



dibles not articulated to the 

 carapace ; appendages of the 

 2nd pair chelate, like those of J PSEUDO- 

 tbe Scorpions. Of small size . \ 8C0BPI0NES. 

 b*. Body short ; abdomen either un- 



segmented or consisting of only 



five somites : generative aperture 



thrust forwards between the coxae 



of the cephalothoracic limbs. 

 a*. Abdomen segmented ; mouth- 

 parts not modified to form a 



suctorial proboscis OPILIONES. 



b*. Abdomen not segmented ; 

 mouth-parts usually modified 

 to form a suctorial proboscis. . ACAlll. 



The present volume deals with the Scorpiones, Uropygi, Amblv- 

 pygi, Solifugae, and with the larger or otherwise conspicuous 

 species of Aranea? (Spiders). 



The Acari (Mites and Ticks) are not likely to be mistaken for 

 any other order. The Opiliones (Harvest Spiders), sometimes 

 called Phalangidea, are, however, frequently confounded with the 

 true Spiders; and the Pseudoscorpiones (False or Book-Scorpions) 

 are often similarly regarded as diminutive Scorpions. Neverthe- 

 less, the key to the orders given above will enable naturalists and 

 collectors to refer any Indian arachnid to its proper systematic 

 position in the Class. 



Order SCORPIONES. 



Integument horny, smooth or granular, usually scantily clothed 

 in parts with short tactile hairs, which are generally longer on the 

 legs and tail than on the trunk. On the segments of the chelae 

 the hairs are often long and bristle-like, and emerge from circular 

 integumental pits with a thickeued rim. The number and posi- 

 tion of these pits, known as setal, setiferoue, or brietU pores, are 

 often of systematic importance. 



Carapace uneegmented and furnished near its centre with a 



