36 



CARBONIFEROUS LAMELLIBRANCHIATA. 



3. Melininse. — " Cartilage divided and distributed along the hinge in a series 

 of furrows crossing the cardinal area at right angles to the hinge-line. Anterior 

 muscular scar generally very small." 



Crenatula, Melina (= Perna, Brug. not Adanson) Bakevellia, Oervillia, Inoceramus, 

 and Pulvinites. 



The affinities of Myalina are discussed, and its close resemblance with 

 Dreissena noted ; two forms, M. perattenuata, M. and H., and M. subquadrata, 

 Shumard, are figured and described. 



The Family Grassitellidse is made to include a large number of dissimilar 

 genera. The Carboniferous genera, Pachydomus, Carbonicola, Pleurophorus, are 

 placed with Astarte, Crassitella, Cardinia, and many others. 



Pleurophorus is stated to be identical with Cleidophorus, Hall, and Pleuropliorus 

 occidentalis, Meek and Hayden, is redescribed and figured from the Coal-measures 

 of Nebraska. 



Under the family Anatinidse, with Thracia, Pandora, Pholadomya, and other 

 recent genera, are grouped Cercomya, Anthracomya, Allorisma, Myacites, 

 ChsBnomya, Arcomya, Mactromya, Goniomya, Gresslya, Cardiomorpha, Ceromya, 

 Sedgwickia, Sanguinolites, and probably Cleobis, and some species of Orthonota ; 

 a classification which cannot be retained for one moment, on anatomical and 

 structural reasons. Allorisma suhcimeata, Meek and Hayden, is redescribed and 

 figured. The genus Sedgwickia is defined and discussed. 8.? Topehaensis, 

 Shumard, and 8.? concava. Meek and Hayden, are described and figured. The new 

 genus Chaenomya, Meek, is defined; and Ghsenomya? Leai'ens7uorthensis,M. and H., 

 equals Allorisma ? Leavensioortliensis, M. and H. ; and G. Gooperi, M. and H., 

 equals Panopaea Gooperi and Allorisma ? Gooperi, M. and H. 



1866. Geinitz's work on the ' Carbon-Formation und Dyas in Nebraska,' was 

 published in 1866. The following Lamellibranchs are described, and some of them 

 figured, from Carboniferous strata : 



Allorisma siihcuneata, Meek and Hayden. 



— LeavensworthensiSjlSILe&k&ndL Hayden. 

 Solemya hiarmica, de Vern. 



Astarte gihhosa, M'Coy. 

 Pecten grandsevus ? Goldfuss. 

 — Missouriensis ? Shumard. 



In 1866 a further paper by Meek and Worthen appeared in vol. i of the 

 ' Proceedings of the Chicago Academy of Nat. Sciences,' p. 11, called " Descriptions 

 of Palaeozoic Fossils from the Silurian, Devonian, and Carboniferous Rocks 

 of Hliuois and other Western States," pp. 13 — 20. 



The following new species are described from Carboniferous beds : 



