7(3 TERTIARY 1N8ECTS OF NOKTB AMERKJA. 



tibia?, 5.5""™; tarsi, 5'"""; third pair of femora, 2.5°""; tibia% 2.4"'"; tarsi, 

 2'""' ; fourth pair of femora, 4.5""' ; tibife, 4.5""" ; tarsi, 5"'"'. 



This species differs from L. cheiracantha in its considerably larger size, 

 tlie absence of distant spines u[)on the legs, and its mucli more slender cepha- 

 lothorax and longer legs. 



Florissant. One /, Nos. 1297G and 13212 and 14032. 



Suborder ORBITELARI^ Thorell. 



The symmetrical-web constructing spiders, though not rare in Tertiary 

 deposits, are not so common as their abundance in recent times would lead 

 one to anticipate, for, as we have seen, only S per cent of the European 

 fossil spiders belong to this group, and all or nearly all of them are Epei- 

 rides. In this number are not included two or three species described by 

 older authors under the name of Aranea, the ])recise location of which is 

 and must probably always remain uncertain. Thirteen species are credited 

 to amber, two to Rott, and one to Oeningen. In our own country the case is 

 very different, for nearly one-half of our species (44 per cent) are to be 

 referred to this group, and all also are Epeirides. It is the one considerable 

 point in which the American fauna may be contrasted with the European. 

 In Rott alone of all the European localities (where the Oi'bitelari;e form one- 

 fourth of the known fauna) do we have any approach to the proportionate 

 number of this great group. (November, 1881.) 



Family EPEIRIDES Sundevall. 



The genera of Epeirides represented in the European Tertiaries are 

 Epeira (five species), of which two come from Rott and one from Oeningen, 

 Grsea (four species), Antopia (three species), Onca (two species), and 

 Epeiridion and Siga (one species each). The American fauna is nearly as 

 rich, richer for once than the amber, whence come all the European species 

 except those specified above, end^racing seven or more species of Epeira, 

 four of an extinct genus, Tethneus, and one each of TetragnathaandNephila, 

 genera before unknown in the fossil state. Not only, then, is the American 

 fauna peculiar for its richness in species of this family, but no other shows 

 so many novel forms for the Tertiary epoch. One of these latter genera pre- 

 dominates in America and the other is a tropical genus, which lends addi- 



' The termiual part of the right tarsi as given in Fig. 27 does not belong to the tarsi. 



