HBMIPTBBA HBTEEOPTBEA GALGULID^!. :H7 



Length of body, 4.2"""; breadth, 1.*.". ...... ; length of hind legs, r>.3o ma 



The species is named for tin- Mas.^ichu-eiN geologist, Prof. B. K. 

 Emerson, of Amherst. 



Florissant. Two specimens, Nos. 3857, 10729. 



Family GALGUL1D> Westwood. 



The only fossil hitherto known as belonging to this family is an in- 

 from the brown c'oal of Ifott, described by Ileyden as a mite under the 

 name Limiiorhares antiipms, but shown by Bertkau to be a galgulid, and 

 probablv only a larval skin of one at that. Bertkau also regards the Flor- 

 issant fossil, described above as a Thysanuran under the generic name 

 Planocephalus, as a \<T\- similar creature and probably a larval galgulid, 

 but in this I can not follow him ; nor are any other Galgulid;c known an;- 

 the mass of insects found at Florissant. In the similar beds at Green Uiver, 

 however, a single insect is preserved (all but the abdomen) which se in> to 

 present characters which show it to be the nearest related to Pelogonus, 

 which, however, I know only from description and the figure of l>ufoiir 

 The present species is very remarkable for several points: the form of the 

 head, the absence of any sign of eyes on the upper surface of tl 

 (darker patches at the outer limits of the head probably indicate their exist- 

 ence at this point beneath), the flattened body, and the I, ig, r..d-like ! 

 the front pair longer and larger than the others, but tpiite similar in char- 

 acter (except for lacking a tarsal joint) and in no way raptorial. It >' 

 certain resemblances to Aphelocheirus, but on the whole seems rather a 

 member of this family than of the Nuucorida-. 



N K( 'Y< i< >N l"S gen iiov (rf.rf, r 

 Body broad oval, apparently much flattened. Bead subsemicircular, 



more than twice as broad as long, the front border stroicjlv and uniformly 

 roimdi-d. hind border truncate, nearly a> broad as the t: . ap- 



parently wholly inferior, situated at the pn-iei:..r outer angles L'"-n-um 

 long, lancet-shaped, not verv >harjily poi..ted. th-- l.i-t joint about a fourth 

 of the total length. Antenna' h.nir ami slender, considerably ! n--er than 

 the width of the body, the li-i joint nearly as IOULT I ' "-- : All tin- 

 legs long, slender, rod-like, -imilar, the femora nowheiv >\\olleii but t., 



