ADDENDA. 

 RECEPTACULITES, De France. 1827. 



ReC'EPTACULITES INFUNDIUULIFORMIS. 



I'LATK XXIV, FIOS. 3-11. 



Cosciwqtora 'mfuiidibtdif<rrmh, ((joldkiiss) Eaton. Qeol. Text Hook. 1833. 



ReceptaciiUUs iufwulibuliformis, (Eaton) Hall. Sixteenth Rc{)t. N. Y. State Cabinet of Nat. Hist., p. 67. 



1863. 

 •• «« " " Report of SUte Geologist for 1882. Expl. pi. 23, fig. 10. 



1883. 

 ReceptaculiUs inonticulatus. Hall. Rejwrt of State Geologist for 1882. Expl. pi. 23, figs. 3-9, 11. 1883. 

 Not Cose'mopora infimdibulifonais, Goldkdss. 



Sponge usu<ally discoid, sometimes broadly infundibuliform. The upper sur- 

 face is more or less depressed with frequently a small conical projection in 

 the center. The summit plates of the spicules are from 1 to 4 mm. in 

 width. The best preserved specimens show prominent nodes or spines at 

 the angles of junction of the cavities left by the solution of the plates of 

 the upper layer, which probably are the fillings of perforations at the angles 

 of the junction of the spicular plates, as described by Dr. J. G. Hinde in 

 R. occidentalis, Salter, (Quar. Jour. Geol. Soc, vol. xl, pi. 37, figs. 3d, f g.) 

 Vertical spicules from 4 to 8 mm. in length and from 1 to 2 mm. in diameter. 

 The largest specimen observed measures 140 mm. across the disk and has a 

 central depressed area 100 mm. in diameter. The smallest specimen yet 

 noticed has a diameter of 29 mm., and the height of the cup is about 15 mm. 



The forms indicated under the name R. monticulatus, in the Report of the 

 State Geologist, prove to be small and better preserved specimens of the 

 original species described by Eaton. 



Formation and locality. In the shaly limestone of the Lower Helderberg 

 group, near Clarksville, Albany county, N. Y. 



