130 TRANSACTIONS OF TIE . [MAR. 17, 
HYOLITHES AMERICANUS, Bill. A 
Theca? triangularis, Hall, Pal. N.Y., vol.i., p. 313, pl. lxxxvii., 
l,a tod. 
Hyolithes Americanus, Bill. Can. Nat., 2d Ser., vol. v., p. 215, 
figs. 2, a and 3, p. 213. 
A fragment shows the prominent ventral ridge characteristic 
of this species. 
Horizon and locality. Upper part of Assise 3 at Hanford 
Brook. Scarce. 
. Hyonirues cf. oprusa, Bill.? 
Salterella obtusa, Bill. Geol. Vermont, vol. ii., p. 955. 
Hyolithes Billingst, Wale. U. 8S. Geol. Sury. Bull. 30, p. 134, 
pl. xiii., figs. 1, a to d. 
A small species of the form of this one occurs in fragments. 
Horizon and locality. Upper part of Assise 3 at Hanford 
Brook. 
HyoLyrHeEs DECIPIENS. PI. vi., figs. 2 a to d. 
Trans. Roy. Soc. Can., vol. xi., p. 96, sec. iv., pl. xvi., figs. 11, 
a to d. 
Horizon and locality. Additional examples of this species 
were found in Assise 2 at Hanford Brook. 
HYOLITHES GRACILIOR, n. sp. Pl. vi., figs. 8 a and b. 
Tube long and slender; angle of incidence of the two edges 
8°. The dorsal side is marked by lines of growth parallel to 
the outline of the lip, which is moderately arched. The ventral 
surface does not show any growth lines and is moderately con- 
vex, The proximal part of the tube is curved. 
Size. Width 3 to 44 mm.; length estimated 25 to 35 mm. 
Horizon and locality. From shales at the top of Assise 3. 
DIPLOTHECA. 
Trans. Roy. Soc. Can., vol. iii., sec. iv., p. 52. 
DIPLOTHECA HYATTIANA. PI. vi., figs. 5a and b. 
Trans. Roy. Soc. Can., vol. iii., sec. iv., p. 52, pl. vi., fig 4, 4 a. 
Found in Assise 3 at Hanford Brook. 
DIPLOTHECA ACADICA, var, CRASSA. PI. vi., fig. 4. 
Trans. Roy. Soc. Can., vol. iii., sec. iv., p. 55. 
Found at the same horizon as the preceding. 
