26 FAUNA OF MAYFIELD'S CAVE. 



Order COLEOPTERA. 

 Family CARABIDAE. 



Anopthalmus tenuis Horn. 



Horn, Trans. Am. Ent. Soc, 1871, 327 (Wyandotte Cave). Cope, Rep. Ind. Geol. 

 Surv., IV, 1872, 177. Packard, 5th Ann. Rep. Peab. Acad. Sci., 1872, 93 (cave 

 at Orleans, Indiana); Am. Nat., x, 1876, 283-287 (Bradford and Wyandotte caves). 

 Hubbard, Proc. Ent. Soc. Wash., i, 1886 (Luray Cave). Packard, Mem. Nat. 

 Acad. Sci., iv, 1888, 15, 18, 80, 84 (Wyandotte, Bradford, and Luray caves). 

 Wickman & Blatchley, Rep. Ind. Geol. Surv., xxi, 1896, 193 (Wyandotte, 

 Sibert's Well Cave, MayfielJ's, Truett's, andShiloh caves, in Indiana). 



Fairly common. This beetle is the only blind one found in the cave. 

 It is suited to life in absolute darkness and to a region of nearly constant 

 temperature, for it has not been observed nearer than 400 feet from the 

 mouth. It is most abundant in the remote part of the cave, where it is 

 seen in damp places, usually crawling over mud or stones. It has been 

 found but twice under stones or drift, situations where the other cave 

 Coleoptera are most abundant. Bait of beef and cheese left under 

 stones at various places to attract insects did not seem to attract this 

 beetle. Only one was found near any bait. The fact that this species 

 is predaceous, while the others are not, accounts for this difference in 

 habit. This beetle is negatively phototropic, and if kept in a jar in a 

 partly darkened room seeks the darkest part of the jar. 



It is a carnivorous species and presumably feeds (cf. Packard, 1876, 

 283) upon the Sinella cavernarum, an occasional spider or mite, and 

 possibly a few small myriapods or dipterous larvae. I have never seen 

 it feed, nor found its eggs or larvae to recognize them. The species is 

 not very abundant, however. 



There is some variation in color. A very light colored individual was 

 taken at ' '42' ' in November, 1904. Instead of being a uniform rufous- 

 brown, the rufous was confined principally to the head and mandibles, 

 to the antennas and prothorax, which were lighter than the head, and 

 to slight traces on the legs and elytra. Its light color seemed not to be 

 due to its being newly emerged, for it was kept alive for ten days and 

 took on no more of the dark color. Another of a series of 10 from 

 Mayfield's was considerably lighter than the average, while of the other 

 8, 3 were slightly darker than the average. 



A series of 17 specimens from the Mitchell caves showed consider- 

 able variation in this respect. Two were quite dark rufous-brown; 

 13 were near the average in color, there being so little difference that 

 their positions in a color series could hardly be determined; 2 others 

 were very light, one having only traces of the brown, the other 



