MiCR. 406 



(Note. Kesembles Salter's Welsh Microdiscus punctatus in 

 Menevian formation. Head resembles Microdiscus daiosord 

 from Middle Cambrian (Saint John) formation. — See also 

 Microdiscus pulchellus,) — Z. C. 

 Microdon hellistrita. See Eodon bellistriata. — VIII c. 



Microdon ellipticus, Whitfield ( Cypricardella elliptica ? 

 y^i J^n Microdon, Conrad, 1842, being a name preoccupied 

 ''"^r-^^^ by Agassiz in 1833 for a genus of fishes, has been 

 changed to Cypricardella. See S. A. Miller's Cat. 

 Amer. Pal. Fossils, p. 194. Hall's Microdon suh- 

 elliptica is described in Trans. Alb. Inst. Vol. 4, 1856. CoUett's 

 1882, plate 30, fig. 37, Spergen Hill, suhcarloniferous., XI 

 Microdon nucleata. See Cypricardella nucleata. — XI 

 Microdon oUonga. See Cypricardella oblonga. — XI 

 Microdon sulelliptica, Cypricardella subelliptica. — XI 



Modiella pygmsea, Hall, Pal. N. Y. Vol. 5, part 1, plate 

 76. He found it with other fossil forms on specs. 808-12,-13 of 

 Fellows' collection at Dingman's creek falls. Pike Co., Pa., 

 from Hamilton strata., VIII c. — See Appendix. 



Modiola angusta, (a mistake for Amnigenia catskil- 

 liensis, Hall, Pal. N. Y. V, i. p. 516), the only fossil seen by 

 Prof. Stevenson in the whole Catsldll formation in Bedford 

 Co., Pa. (T2, p. 75) and that only along the Wills creek out- 

 crop. It occurs in one of the highest beds, bed No. 30 of the 

 Hyndman Section (T2, p. 103) about 300' below the base of 

 the Pocono formation. If this be the one shell only found in 

 the the Oneonta Sandstone of New York, which Hall makes 

 Portage.^ it is remarkable that it is here the one only shell of 

 the Catskill. — IX. — For figure and explanation see Amnige- 

 nia catskilliensis in Appendix. 



Modiola concentrica. Modiomorpha concentrica. VIII c. 



Modiola {mytilops) metella. (Hall, 1870, Prelim, notice 



of Lamell. shells ; Pal. 

 N. Y. Vol. V. plate 33, 

 %. fig. 24, Chemuug.) Clay- 

 \ pole's list of fossils in 

 \ .-^^^i\ Perry Co., Pa., F2, pre- 

 face p. XV. — Chemung- 

 Vol V, PI 33. Catskill leds. VIIIIX. 





