XII. The Insects of the Triassic Beds at Fairplay, Coloeado. 



By Samuel H. Scudder, 



Read May 7, 1890. 



-HiARLY in 1882, Mr. Arthur Lakes, professor in the Colorado School of Mines, discov- 

 ered a bed of plants and insects near Fairplay, Colorado, in rocks much older than any 

 that had before yielded insect remains west of the Great Plains ; the two or three speci- 

 mens he sent me were sufficient to pi'ompt a more thorough exploration of the locality, 

 which T was able to make the following summer, resulting in the discovery of a fauna 

 and a flora of considerable interest. 



The plants have beeu studied by Mr. Lesquereux,^ who pronounces the species, some 

 thirty in number, bvit in a very fragmentary condition, to belong to permiau types, and 

 declares the evidence to be decisive on this point. 



The animal remains consist almost exclusively of insects, and are two-thirds as abun- 

 dant in species as the plants, an exceptionally large ratio in beds where both occur. These 

 insects form an assemblage wholly diflferent from anything before known, and, in con- 

 tradiction to what Mr. Lesquereux says of the plants, clearly belong to types of a more 

 modern character than any the paleozoic series has yet disclosed. It is not often that 

 one may speak so positively in the discussion of fossil insects, especially when not a sin- 

 gle one of the species and only the smaller portion of the genera found have been pre- 

 viously known. But in this case all but two or tlu'ee of the specimens obtained (some 

 eighty in number) belong to a group which of all paleozoic insects has received the most 

 attention, namely, the cockroaches. This great preponderance of cockroaches, and the 

 fact that the known genera found in this collection have hitherto been discovered only in 

 carboniferous and permian rocks, would lead us at first to refer the beds in which they 

 occur to one of the paleozoic series ; but the presence of the other foi'ms, and even the 

 characteristics of those which are referable to carboniferous and permian genera, unmis- 

 takably point to a later horizon. 



As has been repeatedly pointed out by me, paleozoic cockroaches arc distinguished 



'On some specimeus of permian fossil plauts from Colorado. Bull. Mils. Comp. Zool., vii, 243. 



UEMOIIiS BOSTON SOC. NAT. UlST., VOL. IV. 01 C457) 



