58 ENTOMOLOGICAL SOCIETY 



the occurrence of a third cave-inhabiting Silphid which, although 

 provided with fully developed eyes, shows an approach to the 

 genus Adelops in several structural characters. It was discov 

 ered in an hitherto unexplored cave region by Dr. C. Hart Mer- 

 riam, who kindly referred the specimens to me. The species 

 may be described as follows : 



Ptomaphagtis cavernicola, n. sp. Form oblong, convex, finely pubes 

 cent, shining, brownish-piceous, head blackish, mouth-parts and basal 

 half of antennae testaceous, legs brownish-red. Head very finely, not 

 densely punctulate ; eyes flattened, finely but distinctly granulate; a deep 

 transverse impression in front of them ; antennae unusually slender and 

 distinctly longer than head and thorax, joints 2 and 3 each nearly three 

 times longer than wide, joints 4, 5 and 6 gradually decreasing in length 

 but joint 6 is still longer than wide, joints of club very little wider than 

 the funicle, joint 7 slightly longer than wide, joint 8 slightly narrower 

 than the adjoining joints and about one-third the length of joint 7, joints 

 9 and 10 quadrate, terminal joint longer than wide, acuminate. 



Thorax at base about one-third wider than long, sides arcuatedly nar 

 rowing in front, nearly straight behind, base slightly sinuate each side 

 near the hind angles which are distinctly produced and acutely rectangu 

 lar; surface transversely strigose and extremely finely punctulate, the 

 strigae much finer and denser at the sides than in the middle. 



Elytra at base as wide as the thorax, very gradually narrowing apically, 

 sides feebly arcuate, sutural angle slightly produced, surface strigose, the 

 strigae slightly oblique and a little finer and denser than those on the disk 

 of the thorax, sutural stria rather deeply impressed. 



Under side densely punctulate and finely pubescent, mesosternal carina 

 just as strong and abruptedly elevated as in Adelops ; legs very slender, 

 femora densely punctulate, terminal fimbriae of tibiae very minute and of 

 equal length, spurs of hind tibiae of equal length. 



Male : Joints I to 3 of front tarsi distinctly but not strongly dilated. 



Length, 2.7-3 mm. 



Described from four specimens (two of them in rather frag 

 mentary condition) found by Dr. C. Hart Merriam in Marble 

 Cave, Stone Co., in southwestern Missouri. The type, a female 

 (type No. 1424), has been placed in the collection of the U. S. 

 National Museum. 



The species is intermediate in characters between Pto- 

 maphagus and Adelops, having the general appearance and the 

 large eyes of the former and the slender antennas, ante-ocular 

 impression and slender legs of the latter genus. The two genera 

 are structurally so closely allied that there is no room for the 

 establishment of a third intermediate between the two. 



