276 



Letter XXI. which agrees in every respect with the nave 

 encrinite, excepting that the plates composing its base, in- 

 stead of being smooth, are strongly marked by lines form- 

 ing rose-like figures, is in too imperfect a state to allow of 

 its being determined whether it should be considered as a 

 different species from, or merely a variety of, the nave en- 

 crinite. 



An Encrinite is described by M. Guettard, as bearing seve- 

 ral bodies or flowers on the same stalk. M. Guettard ob- 

 serves, that several encrinites of this description were found 

 in Franche Compt6 by M. Loreau ; but M. Walch sus- 

 pects, with reason, that these were rather pentacrinites of 

 the same species with the one described by M. Hiemer, 

 and already noticed. This I therefore consider as not de- 

 serving to be considered as of a distinct species. 



The pentacrinite described by Mons. Davila, as the petrified 

 marine palm, and as exactly agreeing with the recent pen- 

 tacrinite of Madame Boisjourdain, is thought, by M. 

 Walch, of the same species with the preceding. 



From the foregoing enumeration it will appear, that without as- 

 suming the American fossil, Plate XIII. Fig. 36 and 37, which, how- 

 ever, bears strong marks of an affinity with the nave encrinite, and 

 the fossil represented Fig. 80 of the same plate, to be encrinites ; 

 and without reckoning, as probability would almost authorize, that 

 the trochitae, Plate XIII. Fig. 7, 18, 27, 33, and 69, belong to sepa- 

 rate species of these animals, we are yet able to reckon upon the ex- 

 istence of twenty-one decidedly distinct species. 



It cannot but be highly gratifying to the British naturalist to learn, 

 that among her subterranean treasures, Britain can reckon fourteen 

 of the species above enumerated, viz. 1, the cap encrinite; 2, the 

 turban encrinite ; 3, the pear encrinite ; 4, the nave encrinite ; 5, 



