230 TRANS. OF TUNE ACAD. OF SCIENCE. 
ors the latter has fenestrules nearly double as wide as 
the interstices, — ing at the same time strongly corticated, 
at sie: on the reverse. 
It resembles she F. antiqua (Gold sp. Me Coy), but differs 
by the thickness of its interstices, as well as by the ge 
length and fewer number of fenestrules in a given space. 
ity—Permian White Limestone, Guadalupe pe Mou 
tain, New Mexico. 
‘Fenesteria corticata, (Prout.) 
Corrallum wide, loa sis ig wep y res cg 
by the mere insertion of a middle line of fen oat inet 
unknown—that of the pone at losst two age 2 
rays or interstices large, only about one-third 
less than the fenestrules, tubular-striate where worn, the strie 
—— as they ascend between each oscule, from one dis- 
septiment to another, about seven to two 
Fe eons nine cate stout, expanding at junction with rays, 
ound them, non-poriferous ; seven in the _ 
_ Fenestrules nearly as wide as long where worn down, pre 
ng hollow squares with thin sharp edges ; where go 4 
Cell pores in 7 iffic — 
ze cells to each fenestrule, or five counting the two two W 
nts above and bel : 
b tong to the ' 
everse distineth corticated, the surface showing a 
lar line of ies po! a ich ray, W seatte cattered 
Sinem eS: 1 is drawn i 
