42 TAL£0NTOti)GY OF NBW-VORK, 



terior side, the Jissepiment abruptly and deeply bent downwards, and a single ray at this point 

 is obsolete. 



This species has the ordinary external appearance of Streptelasma, for wliich it may be 

 mistaken from its external characters, the cup being usually filled with stony matter. In per- 

 fect specimens the lamellaj are scarcely distinct on the outside, but most of the specimens seen 

 are worn or dissolved so much as to show them very conspicuously. Within the cup the rays 

 are usually curved, and often uniting two or more in one before reaching the centre. The 

 dissepiments bend abruptly downwards near the margin, presenting a deep cavity between the 

 ravs. On the anterior side the dissepiment is bent downwards more deeply, and one ray is 

 carried with it or partially obliterated. This peculiar feature is very conspicuous and charac- 

 teristic. From each side of this depression the lamellae are often almost continuous to the 

 posterior side ; and all the other lamellae from each side join these, leaving a narrow groove 

 or space through the centre of the cup. 



This species possesses the peculiar characters of Canixia, as represented in some of the 

 figures of MiCHELiN and de Konikck, though other species united under the genus have a 

 different structure in addition to this curvature in the dissepiments. 



Fig. 3 a. Posterior view, showing the shorter posterior side and oblique cup, which has about 



4S rays. 

 Fig. 3 b. Anterior side of another specimen, showing the mode of increase by the addition of 



new rays or lamellae. 

 Fig. 3 c. An enlarged view of the cup of another specimen. 

 Fig. 3 d. A longitudinal section, showing the internal characters. 

 Fig. 3 e. A young specimen, lateral view. 



Fig. 3 /. Enlarged view of the cup, showing the irregular union of the lamellEe in the centre. 

 Fig. 3 g-. A large individual : view a little on one side of the anterior face. Ea3'S 50 or more. 

 Fig. 3 h. An irregular form, apparently of this species. 



Position and locality. This species is most abundant at Reynale's basin, and occurs also at 

 Lockport, Niagara county. It is also found at Rochester, associated with Pentamerus oblojig^us, 

 and at the iron ore beds in Wayne county. {State Collection.') 



42;). 1. CYCLOLITES ROTULOIDES (n. sp.). 



Pl. XVII. Figs. 4 a, 6, c, d, e. 

 Compare Madrepora radiis dentatis, ForcT. 1745 ; Linne, Amoen. Acad. t. i, p. 194, f. 5, 1749. 

 Mtidrepora pnrpita. Likne : Gmeli:*, pag. 3756, no. 3. Guettard, Mm. iii, t;ib. 23, 



figs. 4 & 5. 

 Fungia nummismalis. Goldfuss, Petrefacta Germania, pag. 48, pl. 14, fig. 4 a, b. 

 Cyclolites numismalis & C. orbiculata. Lamarck, System, t. ii, p. 233. 

 Cyclolites numismalis. Blaikville, Actinologie, pag. 335, pl. 51, figs. I, 1 a & 1 5. 

 Cyclolites nummismalis, Hisiivgeb, Lethsea Suecica, pag. 100, pl. 28, fig. 5 a, b, c. 



Coral circular, the upper surface convex with a circularly depressed centre, marked by about 

 20 original rays which proceed from the centre, and an equal number of smaller secondary oi 



