Spiders and Their Near Relatives 



The first pair of legs, using the term in the restricted sense 

 just indicated, are the longest of the appendages, and resemble 

 the corresponding appendages of the whip-scorpions in having 

 the tarsi broken up into several segments, each of these legs 

 consisting of twelve segments. The second and third pairs of 

 legs are seven-jointed; the fourth, eight-jointed. 



The respiratory organs, according to the investigation of 

 Miss Rucker foi), consist of three pairs of lung-sacs, which 

 are situated in segments four, five and six of the abdomen, with 

 their corresponding orifices on the ventral surface. These sacs 

 are evidently evaginated through the internal blood-pressure, 

 and invaginated by dorso-ventral muscles, a pair for each 

 pair of sacs. When invaginated, the sacs appear like 

 diminutive tracheae if stretched by the retractor muscles; 

 but if the latter become relaxed, allowing the sac to 

 flatten dorso-ventrally and wrinkle, they appear like diminutive 

 book-lungs. 



The external reproductive organs are quite complicated; 

 they are borne by the second and third abdominal segments. 



It should be borne in mind that this somewhat detailed 

 characterization of the Microthelyphonida is based upon the 

 single known genus of the order; and that the discovery of other 

 genera may necessitate some modifications of it. 



Family KCENENIIDiE (Kcen-e-ni'i-dae) 



As yet only representatives of a single genus, Kanenia 

 (Koe-ne'ni-a) belonging to this order have been found. This is 

 represented in Texas by two species, which will doubtless be found 

 in other parts of the South; and probably other species will also 

 be discovered. 



The genus is widely distributed, species having been found 

 in Italy, Bay of Siam, Chili, and Paraguay, as well as in this 

 country. 



Kanenia lives under stones in company with insects of the 

 order Thysanura. The species are of a translucent white colour 

 except the blades of the chelicerae, which have the yellow tint 

 of thickened chitin. Excellent accounts of our species, Kanenia 

 wheeleri and Kanenia jlorencia, are given by Wheeler ('oo) and 

 Rucker ('01 and '03). 



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