Araneides of the United States. 55 



which has been long felt in this department of our Natural 

 History. 



Class. ARACHNIDES. 

 Order. Pulmonaria. 

 Family. Araneides. 

 Section. Tetrapiieumones. 



Genus. Mygale. Walckenaer. 



Characters. Eyes eighty placed near together ^ on the ante- 

 rior edge of the cephalothorax^ in two roios, variously curved ; 

 fang of the cheliceres articulated doimnuard ; palpi inserted 

 on the extremity of the niaxillce ; feet 4. 1. 2. 3. or 4. 1. 3. 2. 



Observation. The distinction between Mygale and Ole- 

 TERA is artificial, as a slight elongation of the maxillae of My- 

 gale would place the palpi at the side ; witness Mygale ^ 

 nnicolor. 



1. MYGALE TRUNCATA. 



Description. Piceous ; cephalothorax with a curved im- 

 pression behind the middle, cheliceres (mandibulge) terminated 

 by several points above the fang, hairy ; abdomen cylindrical, 

 suddenly truncated at the end, and callous at that place, with 

 concentric grooves and six circular impressions ; thighs more 

 or less rufous at base ; a white membrane between the joints. 



Feet 4. 1. 3. 2. 



Observations. This spider dwells like other species of this 

 subgenus in cylindrical cavities in the earth. Though many 

 specimens were found, I never saw the lid described by au- 

 thors as closing the aperture of its dwelling. The very sin- 

 gular formation of its abdomen, which is as hard as leather 

 behind, and which forms a perfect circle, induces me to believe 

 that it closes, with that part, its dwelling, instead of with 

 a lid, when in danger. 



Habitat. Alabama. 



Fig. 1. Mygale Iruncata. a. Arrangement of thn eyeg. b. Trophi. c. Side 

 view of the ipider. d. Hole in which it resides, c. Respective length of the 

 legs. 



