494 



LAMELLIBRAh CHI A 7 A. 



[MYT. NUC. 



arenacea, see Plethomytilus arenaceus. 

 attenuata, Hall, 1870, Prelim. Notice 



Lam. Shells, p. 23, and Pal. N. Y., vol. 



5, pt. 1, p. 260, Chemung Gr. 

 canadensis, Billings, 1874, Pal. FOBS., vol. 



2, p. 52, Gaspe limestone No. 8, De- 

 vonian, 

 carinata, Hall, 1884, Pal. N. Y., vol. 5, pt. 



1, p. 259, Chemung Gr. 

 chemnngensis, Conrad, 1842, (Inoceramus 



chemungensis,) Jour. Acad. Nat. Sci. 



Phil., vol. 8, p. 246, and Pal. N. Y., vol. 



5, pt. 1, p. 258, Chemung Gr. 



FIG. 862. Mytilarca chemungensis. 



cordiformis, Hall, 1859, (Megambonia cor- 



diformis,) Pal. N. Y., vol. 3, p. 278, 



Low. Held.. Gr. 

 dubia, Walcott, 1885, Monogr. U. S. Geo. 



Sur., vol. 8, p. 168, Devonian, 

 fibristriata, White & Whitfield, 1862, 



(My til us fibristriatus,) Proc. Bost. Soc. 



Nat. Hist., vol. 8, p. 296, and Pal. N. Y., 



vol. 5, pt. 1, p. 264, Kinderhook Gr. 

 gibbosa, Hall, 1884, Pal. N. Y., vol. 5, pt. 



1, p. 262, Up. Chemung Gr. 

 knappi, see Plethomytilus knappi. 

 lata, Hall, 1884, (Mytilops late,) Pal. N. Y., 



vol. 5, pt. 1, p. 262, Chemung Gr. 

 mytilimeris, see Plethomytilus mytilimeris. 

 nitida. Billings, 1874, Pal. Foss., vol. 2, p. 



53, Gaspe limestone No. 8, Devonian, 

 occidentalis, White & Whitfleld, 1862, 



(My til us occidentalis,) Proc. Bost. Soc. 



Nat. Hist., vol. 8, p. 297, and Pal. N. Y., 



vol. 5, pt. 1, p. 263, Kinderhook Gr. 

 oviformis, see Plethomytilus oviformis. 

 percarinata, Whitfield, 1882, Ann. N. Y. 



Acad. Sci., vol. 2. p. 202, Up. Held.Gr., 

 ponderosa, see Plethomytilus ponderosus. 

 pyramidata, Hall, 1884, Pal. N. Y., vol. 5, 



pt. 1, p. 256, Schoharie grit. 

 radiata, see Bvssopteria radiata. 

 regularis, Hall, 1884, Pal. N. Y., vol. 5, 



pt. 1, p. 260, Chemung Gr. 

 sigillum, Hall, 1876, 28th Rep. N. Y. Mus. 



Nat. Hist., p. 174, Niflgara Gr. 

 simplex, Hall, 1884, (Mytilops simplex,) 



Pal. N. Y., vol. 5, pt. 1, p. 261, Che- 

 mung Gr. 

 umbonata, Hall, 1884, Pal. N. Y., vol. 5, 



pt. 1, p. 257, Chemung Gr. 

 MYTILOPS, Hall, 1884, Pal. N. Y., vol. 5, pt. 



1, p. 4. [Ely. from resemblance to 



Mytilus.'] Resembles externally Modiola 

 and Lithodomus. Hinge-line narrow, 

 oblique, extending about half the length 

 of the shell, beaks terminal. Type M. 

 prsecedens. 



FIG. 863. Mytilops prsecedens. Left valve. 



lata, see Mytilaroa lata. 



metella, Hall, 1870, Prelim. Notice Lam. 



Shells, p. 1, and Pal. N. Y., vol 5, pt. 



1, p. 268, Chemung Gr. 



FIG. 864. Mytilops prsecedens. 



prsecedens, Hall, 1870, (Modiola prsece- 

 dens,) Prelim. Not. of Lam. Shells, p. 1, 

 and Pal N. Y., vol. 5, pt. 1, p. 267, 

 Chemung Gr. 



simplex, see Mytilarca simplex. 

 Mytilus, Linnaeus, 1758, Syst. Nat., 10th ed. 

 [Ety. Mytilus, the fish mussel.] This 

 genus does not, so far as known, exist 

 in Palaeozoic rocks. Most of the species 

 referred to it belong to Myalina and 

 Mytilarca. 



concavus, see Myalina concava. 



fibristriatus, see Mytilarca fibristriata. 



occidentalis, see Mytilarca occidentalis. 



ottawensis, Shumard, 1858, Trans. St. 

 Louis Acad. Sci., vol. 1, p. 211, Up. Coal 

 Meas. 



permianus, see Myalina permiana. 



squamosus, Sowerby, 1839, Trans. Geol. 

 Soc. Lond., vol. 4, Permian Gr. Prob- 

 ably not American. 



tenuiradiatus, Shumard, 1858, Trans. St. 

 Louis Acad. Sci., vol. 1, p. 211, Up. Coal 



whitfieldanus, Winchell, 1862, Proc. Acad. 

 Nat. Sci., p. 413, syn. for Mytilarca fibri- 

 striata. 



Naiadites, Dawson, 1860, Acad. Geol., but 

 not defined. The name was used for a 

 genus of plants by Buckman in 1843. 

 The fossils were defined by Salter in 

 1861, under the name of Anthracomya. 



angulatus, see Anthracomya angulata. 



arenaceus, see A. arenacea. 



carbonarius, see A. carbonaria. 



elongatus, see A. elongata. 



leevis, see A. Isevis. 



obtusus, see A. obtusa. 



ovalis, see A. ovalis. 



NUCULA, Lamarck, 1801, Syst. An. sans Vert., 

 p. 87. [Ety. nucula, a little nut.] 

 Equivalve, inequilateral oval, or oblong 



