82 TERTIARY INSECTS OF NORTH AMERICA. 



"mm . 



beyond front, 2.2°™ ; length of first pair of legs, 9.25°"° ; its tibia, 3.25 

 tarsi, 2.4™"' ; second pair of legs, 8°"" ; its tibia, 2.75"°' ; tarsi, 2.4""' ; third 

 pair of legs, 5.5°'°' ; fourth pair of legs, T"" ; its tibia, 2.3°'°' ; tarsi, 2.3°'°'. 

 The measurements are all taken from the female. 



This species is of about the same size as the last, but differs from it in 

 its slenderer form, the shape of the cephalothorax, slight!}' slenderer and 

 less tapering legs, as well as in the clothing of the same. 



Florissant. One <?, three ?, Nos. 8141, 13519 and 13522, 13524 (?), 

 14991 (c?). 



EPEIRA Walckenaer. 



Only a very few species have been described in a fossil state under this 

 generic name. Heyden figured a Gea krantzii from the Miocene beds of 

 Rott on the Rhine which Thorell considers an Epeira and which is about 

 the size of E. delita, but wliicli does not resemble any of our species. Heer 

 figures an Epeira molassica from Oeningen, considerably larger than any 

 of the Florissant Epeirae, but perhaps moi'e nearly resembling E. delita 

 than any of the otliers. Menge names but does not describe an E. eogena 

 from amber, three millimeters long, or of about the size of our smallest spe- 

 cies; and finally Bertkau has more recently described and figured a second 

 species from Rott, under the name of E. troschelii, which bears no small 

 resemblance to our E. meekii, with which also it agrees very well in size. 



Seven species are here described and others indicated, this genus being 

 the only one represented on both continents in Tertiary times which is 

 richer in species in America. The genus is found in all parts of the world, 

 and its occurrence in such numbers in the Florissant beds is a point of no 

 significance beyond the com])arison just made with the European Tertiaries. 

 (October, 1881.) 



Table of the sjyeciea of Epeira. 



Cephalic distinctly separated fmm the thoracic part of the cephalothorax. 



Large species; front of cephalothorax excised in the male 1. E. meekii. 



Small species; front of cephalothorax re<;ularly convex in the male 2. E. nbscondila. 



Cephalic and thoracic portions of the cephalothorax completely blended. 

 Abdomen narrowed in front and behind. 



Abdomen distinctly ovate 3. E. delitu. 



Front of abdomen quadrate, as broad as iu the middle 4. E. cinefacta. 



Abdomen nearly globular. 



Larger species ; abdomen smaller than cephalothorax 5. E. vucanalis. 



Smaller species ; abdomen larger than cephalothorax 6. E. emertoni. 



