PRO.] 



BRACHIOPODA. 



363 



Nat. Hist., p. 177, and Pal. N. Y., vol. 



4, p. 182, Chemung Gr. 

 bialveata, Hall, 1867, Pal. N. Y., vol. 4, p. 



183, Chemung Gr. 

 boydi, Hall, 1857, (Productus boydii,) 



10th Rep. N. Y. St. Mus. Nat. Hist., p. 



179, and Pal. N. Y., vol. 4, p. 169, Che- 

 mung Gr. 



concentrica, Hall, 1857, (Productus con- 

 centricus,) 10th Rep. N. Y. St. Mus. 

 Nat. Hist., p. 180, Kinderhook Gr. 



costatula, Hall, 1867, Pal. N. Y., vol. 4, p. 



180, Chemung Gr. 



costatula var. strigata, Hall, 1867, Pal. 

 N. Y., vol. 4, p. 181, Chemung Gr. 



dmimilis, see P. hallana. 



dumosa, Hall, 1861, (Productus dumosus,) 

 14th Rep. N. Y. St. Mus. Nat. Hist., p. 

 99, and Pal. N. Y., vol. 4, p. 162, 

 Ham. Gr. 



eriensis, Nicholson, 1874, Geo. Mag., n. s., 

 vol. 1, p. 118, Cornif. Gr. 



exanthemata, Hall, 1857, (Productus ex- 

 anthematus,) 10th Rep. N. Y. St. Mus. 

 Nat. Hist., p. 174, and Pal. N. Y., vol. 

 4, p. 163, Ham. Gr. 



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

 Sur., vol. 8, p. 130, Ham. Gr. Pro- 

 posed instead of P. dissimilis of Hall, 

 which was preoccupied by DeKoninck. 



Fig. 599.— Productella hirsuta. 



hirsuta, Hall, 1857, (Productus hirsutus,) 



10th Rep. N. Y. St. Mus. Nat. Hist., p. 



175, Chemung Gr. 

 hirsuta var. rectispina, Hall, 1867, Pal. 



N. Y., vol. 4, p. 168, Chemung Gr. 

 hystricula, Hall, 1867, Pal. N. Y., vol. 4, 



p. 178, Chemung Gr. 

 lachrymosa, Conrad, 1842, (Strophomena 



lachrymosa,) Jour. Acad. Nat. Sci., vol. 



8, p. 256, and Pal. N. Y., vol. 4, p. 174, 



Chemung Gr. 

 lachrymosa var. lima, Conrad, 1842, 



(Strophomena lima,) Jour. Acad. Nat 



Sci., vol. 8, p. 256, and Pal. N. Y., vol 



4, p. 174, Chemung Gr. 

 lachrymosa var. stigmata, Hall, 1867, Pal 



N. Y., vol. 4, p. 174, Chemung Gr. 

 navicella, Hall, 1857, (Productus navi 



cella,) 10th Rep. N. Y. St. Mus. Nat 



Hist., p. 172, and Pal. N. Y., vol. 4, p 



156, Cornif. and Ham. Grs. 

 newberryi, Hall, 1857, (Productus new- 



berryi,) 10th Rep. N. Y. St. Mus. Nat 



Hist., p. 180, Chemung Gr. 

 onusta, Hall, 1867, Pal. N. Y., vol. 4, p 



184, Chemung Gr. 

 pyxidata, Hall, 1858, (Productus pyxi- 



datus,) Geo. of Iowa, p. 498, Ham. Gr, 



rarispina, Hall, 1857, (Productus raris- 

 pinus,) 10th Rep. N. Y. St. Mus. Nat. 

 Hist., p. 178, and Pal. N. Y., vol. 4, p. 

 170, Chemung Gr. 



shumardana, Hall, 1858, (Productus shu- 

 mardanus,) Geo. Rep. of Iowa, vol. 1, 

 pt. 2, p. 499, and Pal. N. Y., vol. 4, p. 

 157, Up. Held. Gr., Marcellus shale, 

 Ham. and Chemung Grs. 



speciosa, Hall, 1857, (Productus specio- 

 sus,) 10th Rep. N. Y. St. Mus. Nat. 

 Hist., p. 176, and Pal. N. Y., vol. 4, p. 

 175, Chemung Gr. 



spinulicosta, Hall, 1857, (Productus spin- 

 ulicostus,) 10th Rep. N. Y. St. Mus. 

 Nat. Hist., p. 173, and Pal. N. Y., vol. 

 4, p. 160, Marcellus shales and 

 Ham. Gr. 



striatula, Hall, 1867, Pal. N. Y., vol. 4, p. 

 177, Chemung Gr. 



subaculeata, Murchi- 

 son, 1840, (Productus 

 subaculeatus,) Bui. 

 Soc. Geo. de France, 

 vol. 11, p. 255, and 

 Pal. N. Y., vol. 4, p. 

 154, Waverly Gr. 



subalata, Hall, 1857, ^ 



(Productus subala- ^ffla^v^S 



tus,) 10th Rep. N.Y. valve. 



St. Mus. Nat. Hist., 



p. 174, and Pal. N. Y., vol. 4, p. 165, 



Ham. Gr. 



truncata, Hall, 1857, (Productus trunca- 

 tus,) 10th Rep. N. Y. St. Mus. Nat. 

 Hist., p. 171, and Pal. N. Y., vol. 4, p. 

 160, Marcellus shales and Ham Gr. 



tullia, Hall, 1867, Pal. N. Y., vol. 4, p. 

 164, Ham. Gr. 

 Productus, Sowerby, 1812, Min. Conch., 

 vol. 1, p. 153. [Ety. productus, pro- 

 duced — so named from one valve of 

 the shell being prolonged beyond the 

 other, and often to a great extent.] 

 Shell inequivalve, transverse, or elon- 

 gated with auricular expansions ; ven- 

 tral valve convex, geniculated, or per- 

 pendicularly incurved ; hinge-line 

 straight; area narrow, or the cardinal 

 edge thickened ; beak incurved ; in the 

 interior a narrow mesial ridge separates 

 two elongated, ramified, muscular ad- 

 ductor scars ; under and outside these are 

 two deep,dongitudinally subquadrate im- 

 pressions for cardinal muscles, widely 

 separated by a crest, and lower down 

 toward the center of the shell two deep 

 concave subspiral depressions for spiral 

 or labial appendages ; dorsal valve con- 

 cave, following the other valve ; cardi- 

 nal process for the attachment of mus- 

 cles prominent, trifid, and below it a 

 mesial ridge, upon each side of which 

 are the ramified adductor scars ; out- 

 side and in front of these are two reni- 

 form impressions ; a prominence on 

 each side the mesial ridge indicates the 

 origin of spiral arms ; surface of shell 

 striated, more or less concentrically 



