ANIMALS. 17 



Order Stichostegia, D'Orbigny. 

 Genus DentaUna, D'Orb. 

 Generic characters. — Shell elongate, conical, equilateral, slightly curved ; formed of 

 a series of chambers, more or less globose, arranged end to end, on a single axis. 

 Aperture small, round, on apex of the last chamber. 



No. 1. Dentalina Permian a, nob. Tab. VI, fig. 1. 



INCH. 



Length, Jg- 

 Thickness, -^^-g 



Shell formed of about nine smooth, oval cells. The early cells subglobose, the 

 later cells longer than broad. Last cell somewhat beaked. Sutures shallow. 



Not rare, both in the young and adult state, at Byers' Quarry. 



Several species of Dentalina approach this form, especially D. elegans, D'Orb. 

 (tertiary), Foram. foss. Vienne, p. 45, n. 21, tab. i, figs. 52-6, and T). gracilis, D'Orb. 

 (cretaceous), Mem. Soc. Geol. France, tom. iv, V^ partie, p. 14, n. 4, tab. i, fig. 5. 



No. 2. Dentalina Kingii, noh. Tab. VI, figs. 2, 3. 



INCH. 



Length, ^L 

 Thickness, -j^ 



Shell formed of about eight globose cells, each bearing ten to twelve ribs. Sutures 

 excavated. 



Of frequent occurrence, at Byers' Gluarry. 



D. Kingii is very similar to B. multicostata, D'Orb. (cretaceous), Mem. Soc. Geol. 

 France, tom. iv, V^ partie, p. 15, n. 8, tab. i, figs. 14, 15 ; which latter, however, has 

 more than double the number of ribs. This form is closely allied to that of 

 Nodosaria sulcata, Nilss. (cretaceous), Nod. elegans, Milnst. (tertiary), Nautilus ohliquus, 

 Gualt. (recent), N.jugosus, Montag. (recent), and Nod. Rapa, D'Orb. (recent). 



No. 3. Dentalina (?) Tab. VI, fig. 4. 



INCH. 



Length, ^\ 

 Thickness, -^-^ 



Crystalline and transparent cast of shell formed of two oval, oblique cells ; last 

 cell beaked; each cell marked with a diagonal fold, as if it were a tube bent on 

 itself. 



We have met with three instances of this anomalous fossil, in the same locality as 

 the last. 



c 



