Superfamily Avicularioidea 



As to the habits of the species Hentz adds the following: 

 "This spider dwells ... in cylindrical cavities in the 

 earth. Though many specimens were found, I never saw 

 a lid. . . . The very singular formation of its abdo- 

 men, 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." 



The observations of Hentz were made in Alabama. Al- 

 though he states that he found many specimens, it is 

 evidently a rare species now. Mr. N. Banks writes me that 

 he has a single female in his collection. This was taken in 

 Louisiana. 



Genus BOTHRIOCYRTUM (Both-ri-o-cyr'tum) 



The tibia of the third legs lacks the depression found in 

 Pachylomerus; the tarsi of the first and second pairs of legs are 

 not scopulate, but are furnished with strong spines; the tarsal 

 claws are armed with but few teeth, in most cases with a single 

 tooth, where there are more than one they are in a single series. 

 The clypeus is nearly horizontal, and is twice as broad as the trans- 

 verse diameter of the anterior lateral eyes. 



Only two species of this genus have been described; one 

 of them is the common California species, the other is a Mexican 

 species which perhaps also occurs in our fauna. 



The Common Californian Trap-door Spider, Bothriocyrtum 

 californicum (B. cal-i-for'ni-cum). — The adult female measures 

 one and one sixth inches in length. When alive the general colour 

 of the whole spider is a dark blackish chocolate brown, the legs 

 and cephalothorax being darker than the abdomen. In alcohol, 

 the cephalothorax is deep reddish yellow brown; and the abdomen 

 a dull yellowish brown colour. The sternum is not marked by 

 sigilla. The anterior tarsi have only a single tooth at the base, 

 those of the posterior tarsi have at the base four slender and 

 recurved teeth of which the second and the fourth are longer 

 than the others. 



This is the species whose nest is most often seen in collections. 

 The nest is an unbranched tube furnished with a single door of 

 the cork type. 



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