56 TEETIAEY INSECTS OF NORTH AMERICA. 



Length of body, 7.65 mm ; cephalothorax, 4.2 mra ; abdomen, 3.5 mm ; 

 breadth of cephalothorax, 1.7 mm ; abdomen, 3.2 mm . 



The legs are imperfect in the single specimen known, and as no palpi 

 are preserved the sex is uncertain. The species differs from both the pre- 

 ceding in its much larger size: from P. resurrectus also in its very quadrate 

 cephalothorax, and from P. evocatus in its globular abdomen. 



Florissant. No. 9823. 



Suborder LATERIGRAD^E Thorell. 



The two families of crevice-inhabiting crab-spiders which have been 

 found fossil in Tertiary deposits, Thomisides and Philodrominpe, are both 

 (the former particularly) common at the present day in Europe and North 

 America. The fossil species belong mostly to the former, only four species 

 of Philodrominaj having been recorded, all from amber, while twenty-one 

 Thomisides are known, not including those described below, all of which 

 also fall here. In this statement the strange amber genus Archsea is not 

 included, since, though placed by both Menge and Thorell in this group, 

 it differs strikingly from the other members and should form a family group 

 apart from them, having no known affinities with any of the species from 

 the stratified deposits of Europe or America. (November, 1881.) 



Two additional species of Thomisides have lately been described from 

 Aix by Grourret. (October, 1889.) 



Family THOMISIDES Sundevall. 



All but four of the fossil Thomisides described up to the present time 

 come from amber and represent the genera Athera (one species), Clythia 

 (five species), Ocypete (four species), Opisthophylax (one species), Syphax 

 (five species), and Thornisus (one species). Thomisus is also represented, 

 with Xysticus, by two species each in the stratified deposits of Oeningen 

 and Rott, the latter locality furnishing one Xysticus, the former the remain- 

 ing species. The species described below appear pretty certainly to fall in 

 the Thomisides proper and probably also in the vicinity of Thomisus or 

 Xysticus. The family is widely distributed in all parts of the world. 

 (November, 1881.) 



The two species recently described by Gourret from Aix are regarded 

 as types of extinct genera which he terms Amphithomisus and Pseudotho- 

 misus. (October, 1889.) 



