chamberlin: new spiders of the family aviculariidae. 73 



BRACHYBOTHRIINAE. 



Brachybothrium pugnax,' sp. nov. 



Type. — M. C. Z. 115. 9. Arizona: Tucson. Charles Bendire. 



Carapace and legs light brown of dilute chestnut tinge. Chelicerae 

 dusky chestnut. Sternum and coxae of legs beneath dusky brown. 

 Abdomen light brown, dusky especially beneath; spinnerets yellowish. 



Pars cephalica rather low, with the posterior declivity somewhat 

 flattened; in profile moderately convex. Fovea thoracica short, 

 very deep, radiating lines fine, more or less ramose and in part reaching 

 the fovea. 



Anterior median eyes with centers on or near the middle transverse 

 line of ocular area; very close to and not much differing in size from 

 the posterior median eyes. 



Chelicerae moderate; the cephalothorax about two and a half 

 times longer than their anteroposterior length. Rastellum composed 

 of a moderate number of long, stout, distally curved spine-like teeth.^ 

 Hairs long and numerous on elevation at mesal side of the convex 

 surface. 



The femur of the palpus is conspicuously compressed laterally; the 

 tibia is ventrally flattened over the distal portion, narrowed distad; 

 tarsus similarly flattened and depressed at distal end beneath so that 

 the more proximal portion protrudes as a lobe; tibia and tarsus 

 strongly spined. Claw with four teeth. 



Metatarsus I produced ventrad into a conspicuous, basally long and 

 distally angular lobe a little proximad of middle, with a lower, keel- 

 like edge extending from this lobe to the distal end of the joint; the 

 lobe clothed with long fine hairs. Tibia I with a ventral ridge con- 

 spicuously highest near middle as in the metatarsus; on the tibial 

 lobe are borne 5 or 6 long black spines in 2 series (2 -j- 3 or 2 + 4, the 

 larger number being in the series on the mesal or anterior side). 



Distal article of the superior spinnerets longer and clearly mdre 

 slender than the median one. 



Female (type). Length, 13 mm. 



Cephalothorax: length, 7 mm.; width, 6 mm. 



' pugnax, pugnacious. 



• No rastellum proper is present on the left chelicera in the type, though strongly developed 

 on the right one. The left chelicera is smaller aliio. 



