BYRRHIDJE. 93 



ni the older Tertiaries of Oeningeii and the Rhine, and another in amber. 

 In America t\vo fossil species are known, one from the Canadian Pleistocene, 

 the other from the Oligocene of Colorado. 



The Florissant species here described agrees tolerably well in structure, 

 as far as can be seen, with modern types, but has certainly a much more 

 regularly oval contour to the body. The head is retractile; while in the 

 species described from the European Tertiaries, or those best figured, it 

 does not appear to be so, so that they are probably wrongly placed here, 

 belonging rather to the Nosodendrinse. 



BYRRHUS OTTAWAENSIS. 

 Byrrlttf* ,,tt<iw<t<>nx! Srudd.. Contr. Canad. Palfeont., II, 40-41, pi. 2, figs 6-8 (18Ui'). 



Greene's Creek, Ottawa River, Canada. Since the description was pub- 

 lished, a second specimen of this species has been found at the same locality, 

 by Dr. II. M. Ami. 



BYRRHUS ROMINGERI sp. nov. 

 PI. X, fig. 9. 



A species of about the size of B. geminatus LeC. and agreeing fairly well 

 with it in the sculpturing of the elytra and the granulation of the under sur- 

 face of the abdomen, but differing from the Byrrlii in the more regular 

 contour of the oval body, the lack of a humeral thrust at the base of the 

 elytra, and the want of any prominence to the head. The antennae are as 

 long as half the width of the body, the joints increase more gradually in 

 size than in B. (/I'm/i/atttv, and the last joint has a greater proportionate 

 size. The hind tibiae are slender, but little expanded, and scarcely half as 

 wide as the femora; the hind tarsi are apparently cpiite as in the modern 

 species. The elytral striation is indistinct and apparently of much the 

 same character as in B. geminatus. 



Length, 5.25 ram.; breadth, 3.75mm. 



Florissant, Colorado; three specimens, Nos. 7700, 8124, and of the 

 Princeton collection, No. 1.540. 



Named for the Michigan geologist, Carl Rominger. 



