228 



Alexander Petrunkevitch, 



Family Dysderid^. 



Characters of the family: — Two pairs of spiracles, the first of 

 which belongs to lung-books, the second to tracheal tubes. Six 

 eyes. Chelicerse long and obliquely inclined. Lip very long. 

 Maxillary lobes parallel. Anterior coxae long, cylindrical Six 

 spinnerets, anterior and posterior ones of about the same length 

 while the median ones are sometimes shorter. Colulus present. 

 Tarsi with two or three claws, upper claws with a single series of 

 teeth, median claw smooth. 



The sub-family Segestriinse is characterized by the shape of the 

 sternum which is much as in other spiders. The two genera, 

 Segestria and Ariadna, of which the sub-family is composed, are 

 separable by the position of their eyes and the structure of cheli- 

 cerse. Both genera are widely distributed. 



Genus Segestria Latreille. 

 Segestria sccessa Scudder {Text figure 5). 



Scudder, Tertiary Insects, 1890. P. 61. PI. 11. fig. 28. 

 Two females, one of these being No. 205 (now No. 71) of the 

 Scudder Collection of the Museum of Comparative Zoology of 

 Harvard University, the other Nos. 1806 and i8i8of the Princeton 

 Collection. Both from Florissant. 



Figure 3. — Segestria secessa Scudder. Specimen No. 205 (71). 

 first left; b, fourth left, x 13. 



Legs 



The Harvard specimen is the type of the species and the only 

 one which I have examined. It is a beautifully preserved speci- 

 men although the impression is rather faint. The spiracles are 

 altogether indiscernible. The claws are too poorly preserved to 



