LAMELLIBRANCHIATA. 485 
Classification of paleozoic Lamellibranchiata.] 
CLASSIFICATION OF PALEOZOIC LAMELLIBRANCHIATA. 
Subkingdom MOTmUSG A: 
cass LAMELLIBRANCHIATA, Biainvite. 
order ASTPHONIDA, wWooawara. 
Mantle lobes separate, siphons wanting. Pallial line without sinus. 
Suborder MONOMYARIA. 
A single adductor muscle, the anterior one wanting. 
Family PECTENIDA#, Lamarck. 
GENERA: Aviculopecten, McCoy; Crenipecten, Hall; Euchondria, Meek; Lyriopecten, Halil; Pernopecten, 
Winchell; Pterinopecten, Hall; Streblopteria, McCoy. 
Suborder HETEROMY ARIA. 
Anterior adductor muscle very small, the posterior one large. 
Family AVICULIDAS, dOrbigny. 
GENERA: Actinopteria, Hall; Bakevellia, King; Ectenodesma, Hall; Glyptodesma, Hall; Liopteria, Hall; 
Leptodesma, Hall; Limoptera, Hall; Monoptera, Meek and Worthen; Monotis, Bronn; 
? Paleopinna, Hall; Posidonomya, Bronn; Pseudomonotis, Beyrich; Pterinea, Goldfuss ( Ver- 
tumia, Hall); Pteronitella, Billings; Pteronites, McCoy; ? Ptychopteria, Hall. 
Family PINNIDA®, Gray. 
GENERA: Aviculopinna, Meck; Pinna, Linne. 
Family AMBONYCHIIDA#, Miller. 
GENERA: Allonychia, Ulrich; Ambonychia, Hall (restricted); Amphicelia, Hall; Anomalodonta, Miller; 
Anoptera, Ulrich; Byssonychia, Ulrich; Byssopteria, Hall; Clionychia, Ulrich ; Eetéfoptera,,. 
Ulrich; Fridonychia, Ulrich; Mytilarea, Hall; Paleocardia, Hall; Plethomytilus, Hall. 
Psilonychia, Ulrich. 
Family CHASNOCARDIID AS, Miller. 
GENERA: Chenocardia, Meek and Worthen; Megambonia, Hall. 
Family MYTILIDA®S, Lamarck. 
GENERA: ? Anthracomya, Salter; ? Anthracoptera, Salter; Gosselettia, Barrois; Lithodomus, Cuvier ( Litho- 
phaga, Bolton); Modiella, Hall; Modiola, Lamarck ; Myalina, Koninck; Mytilops, Hall; 
2 Spathella, Hall. ~ 
Family MODIOLOPSID/4, Ulrich. 
UShilincr 
GENERA: Actinomya, Ulrich; ? Aristerelld, Ulrich; Colpomya, Ulrich; ? Cymatonota, Ulrich; ? Cypricardella, 
Hall; ? Endodesma, Ulrich ; Eurymya, Ulrich; Goniophora, Phillips; Modioledon, /Ulrich ; 
Modiolopsis, Hall; Modiomorpha, Wall; Orthodesma, Hall and Whittield; ? Prolobella, Ulrich; 
? Psiloconcha, Ulrich; ? Pyanomya, Miller. 
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