196 



CCELENTERATA. 



[MIC. MON. 



MICHELINIA, DeKoninck, 1842, Descrides 

 Anim. Foss. Belg., p. 20. [Ety. proper 

 name.] Cprallum composite, forming 

 hemispherical, depressed, or pyriform 

 masses of prismatic or subcylindri- 

 cal corallites; mural pores ; tabulae ; tubes 

 having striae or ridges ; epitheca con- 

 centrically wrinkled, with root-like pro- 

 longations. Type M. favosa. 



Fi. 191. Megalograptus welchi. Frond, show- 

 cells and spiuous processes. 



convexa, D'Orbigny, 1850, Prodr. de Pale- 

 ont, t. 1, p. 107, Onondaga and Cornif- 

 erous Grs. 



dividua, Hall, 1876, Illust. 

 Dev. Foss., pi. 18, Ham. 

 Gr. 



eugenea?, White, 1884, 13th, 

 Rep. Geo. Ind., p. 119, 

 Coal Meas. 



expansa, White, 1880, 12th 

 Rep. U. S. Geo. Sur. 

 Terr., p. 158, Waverly Gr. 

 favositoidea, Billings, 1858, 

 Rep. of Progr. Can. Geo. 

 Sur., p. 175, Up. Held. 

 Gr. 

 insignis, Rominger, 1876, Foss. Corals, 



675, Up. Held, and 

 am. Gr. 

 intermvttens, Billings, 1859, 



Can. Nat. and Geo. Sur., 



vol. 4, p. 113, Cornifer- 



ous Gr. 

 lenticularis, Hall, 1874,26th 



Rep. N. Y. St. Mus. Nat. 



Hist., p. 113, Low. Held. 



Gr. 

 placenta, White, 1880, 12th 



Rep. U. S. Geo. Sur. Terr., 



p. 157, Waverly Gr. 



FIG. 



Miclieli n ia 

 ugenere. An- 



stvlopora, Eaton, 1832, 

 ra ) Geo . 



40, and larger coral- 



(Astrea stylopora ) Geo .*' 



Text book, p 

 Illust. Dev. Foss., pi. 18, 

 Ham. Gr. 



trochiscus, Rominger, 1876, Pal. Foss., p. 

 76,syn. for Pleurodictyum americanum. 

 MICROCYCLUS, Meek & Worthen, 1868, Geo. 

 Sur. 111., vol. 3, p. 420. [Ety. mikros, 

 small ; kuklos, circle.] Corallum free or 

 with a minute central point of attach- 

 ment, discoidal; no columella; calice 

 shallow, with a single fossula; septa 

 short, radiating regularly, or those 

 nearest the fossette converging a little 



toward its sides; epitheca well de- 

 veloped. Type M. discus. 



discus, Meek & Worthen, 

 1868, Geo. Sur. 111., vol. 

 3, p. 420, Ham. Gr. 

 Millepora repens, see Alveo- 



lites repens. 



MONOGRAPTUS, E m m o n s , 

 1856, (Monograpsus,) 

 Am. Geo., p. 106. [Ety. FIG. l94.-Micro- 

 monos, one; grapho, I cyclus discus ' 

 write.] Serrations confined to one edge 

 of the stipe; axis none. Type M. ele- 

 gans. 



convolutus var. coppingeri, Etheridge, 

 1878, Quar. Jour. Geo. Soc., vol. 34, p. 

 577, Silurian. 



elegans, Emmons, 1856, Am. Geo., p. 106, 

 Up. Taconic. 



rectus, Emmons, 1856, Am. Geo., p. 107, 



Up. Taconic. 



MONOTRYPA, Nicholson, 1879, Pal. Tab. Cor- 

 als, p. 320. [Ety. monos, one; trupa, 

 hole.] Corallites of two kinds; the 

 larger aggregated into clusters (monti- 

 cules); the smaller occupying the space 

 between the monticules; both larger 

 and smaller thin-walled, polygonal tab- 

 ulae remote. Type M. undulata. This 

 was proposed as a subgenus for Monti- 

 culipora; upon microscopial examina- 

 tion and upon such a state of facts, I 

 prefer, at present, to leave the species 

 under the genus Monticulipora. 



(?)spinulosa, Hall, 1887, Pal. N. Y., vol. 1, 



p. 67, Low. Held. Gr. 



MONOTRYPELLA, Ulrich, 1882, Jour. Cin. Soc. 

 Nat. Hist., vol. 5, p. 153. [Ety. mono- 

 trypa ; and illus, diminutive.] Ramose, 

 smooth or tuberculated, cells of one 

 kind only; walls thin, in the axial re- 

 gion, and thicker toward the periphery ; 

 diaphragms straight; no spiniform 

 tubuli. Type M. aequalis. 



abrupta, Hall, 1879, (Chetetes abruptus,) 

 32d Rep. N. Y. St. Mus. Nat, Hist., p. 

 148, Low. Held. Gr. 



sequalis, Ulrich, 1882, Jour. Cin. Soc. Nat. 

 Hist., vol. 5, p. 247, Hud. Riv. Gr. 



arbuscula, Hall, 1887, Pal. N. Y., vol. 6, p. 

 12, Low. Held. Gr. 



briareus, Nicholson, 1875, (Chetetes bri- 

 areus,)0hio 

 Pal., vol. 2, 



. 202, Utica 

 late. 



consimilis, 

 Hall, 1876, 

 (Chetetes 

 consimilis, ) 

 28th Rep. 

 N. Y. St. 

 Mus. Nat. 

 Hist., p. 110, 

 Niagara Gr. 

 densa, Hall, 

 1874, (Trem- 



atopora densa,) 26th Rep. N. Y. St. 

 Mus. Nat. Hist., p. 105, Low. Held. Gr. 



FIG. 195. Monotrypella quad- 

 rata, natural size and mag- 

 nified. 



