BIOLOGICAL CLASSIFICATION. 1419 



Family SPIRIFERED/E King. 



Cyrtia Dalman, Reticularia McCoy (subgenus Prosserella Grabau), Spirifer Sowerby 

 (subgenera Delthyris Dalman, Eospirifer Schuchert). 



Family SUESSID^E Waagen. 

 Cyrtina Davidson. 



Family RHYNCHOSPIRID^S Hall and Clarke. 



Homoeospira Hall and Clarke, Rhynchospira Hall and Clarke, Trematospira Hall. 

 Family MERISTELLID^E Hall and Clarke. 



Hindella Davidson (subgenus Greenfieldia Grabau), Hyattidina Schuchert, Merista 

 Suess, Meristella Hall, Meristina Hall, Meristospira Grabau, Nucleospira Hall, 

 Whitfieldella Hall and Clarke. 



Family CCELOSPIRID^S Hall and Clarke. 

 Anabaia Clarke, Coelospira Hall. 



Family ATHYRID^E Phillips. 

 Athyris McCoy. 



Phyllum MOLLUSCA. 

 Class PELECYPODA. 

 Order PRIONODESMACEA. 



Family SOLENOMYID,E Gray. 

 Cliiioj)istha Meek and Worthen, Solenomya Lamarck. 



Family GRAMMYSIUXE Fischer. 



Cuneamya Hall and Whitfield, Edmondia Dekoninck, Grammysia Verneuilj Lepto- 

 domus McCoy, Saffordia Ulrich, Sedgwickia McCoy. 



Family CTENODONTID^E Dall. 

 Ctenodonta Salter, Nuculites Conrad, Pyrenomoeus Hall. 



Family PARARCID^ Ulrich. 

 Panenka Barrande. 



Family LEDID^E Adams. 



Clidophorus Hall, Cytherodon Hall. 



Family MEGALODONTID^E Zittel. 

 Megalomus Hall, Plethocardia Ulrich. 



Family CYRTODONTID^E Ulrich. 



Bodmania Miller, Cyrtodonta Billings, Ischyrodonta Ulrich, Matheria Billings, Orto- 

 nella Ulrich, Sowteria Whiteaves, Vanuxemia Billings, Whitella Ulrich. 



Family AVICULID^E D'Orbigny. 



Actinopteria Hall, Avicula Klein, Cliopteria Williams, Leptodesma Hall, Limoptera 

 Hall, Leiopteria Hall, Palseopecten Williams, Pterinea Goldfuss, Pteronitella 

 BilHngs, Ptychopteria Hall, Rhbmbopteria Jackson, Tolmaia Williams. 



Family AMBONYCHIID/E Miller. 



Allonychia Ulrich. Ambonychia Hall, Amphiccelia Hall, Anomalodonta Miller, 

 Anoptera Ulrich, Byssonychia Ulrich, Clionychia Ulrich, Ectenoptera Ulrich, 

 Eridonychia Ulrich, Mytilarca Hall, Opisthoptera Meek, Paleocardiallall, Pletho- 

 mytilus Hall, Psilonychia Ulrich, Streptomytilus Kindle and Breger. 

 84243 Bull. 92 vol 215 45 



