North American Palaeozoic Crustacea. 



15 



penn£e-dsdali, Etheridge, Woodward & Jones, 1884 ; 2d Kept. Comm. 



Fossil Phyllopoda Pal. Rocks, p. 11. 

 peniiJB-dffidali, id., 1885 ; 3d Rept. Comm. Fossil Phyllopoda Pal. Rocks, 



p. 3. 

 penuffi-dffidali. Hall & Clarke, 1888 ; Pal. New York, vol. 7, p. 200, pi. 35, 



fig. 24. 



peniije-dffidali, Etlieridge, Woodward, & Jones, 1888 ; 6th Rept. Comm. 

 Fossil Phyllopoda Pal. Rocks, p. 9. 



pes-cervse, Clarke, 1883 ; Am. Jour. Sci., 3d series, vol. 25, 123, figs. 4, 5. 



Chemung. 



pes-cervje, Jones & Woodward, 1884; Geol. Mag., Dec. 3, vol. 1, p. 349. 



pes-cervffi, Etheridge, Woodward, & Jones, 1884 ; 2d Rept. Comm. Fossil 

 Phyllopoda Pal. Rocks, p. 11. 



pes-cervse, id., 1885 ; 3d Rept. Comm. Fossil Phyllopoda Pal. Rocks, p. 3. 



pes-cervje, Hall & Clarke, 1888 ; Pal. New York, vol. 7, p. 202, pi. 35, 

 figs. 20, 21. 



pes-cervje, Etheridge, Woodward, & Jones, 1888 ; 6th Rept. Comm. Fossil 

 Phyllopoda Pal. Rocks, p. 9. 



procne, Clarke, 1883 ; Am. Jour. Sci., 3d series, vol. 25, p. 122, figs. 2, 3. 



Chemuug. 



procne, Jones & Woodward, 1884 ; Geol. Mag., Dec. 3, vol. 1, p. 349. 



procne, Etheridge, Woodward & Jones, 1884; 2d Rept. Comm. Fossil 

 Phyllopoda Pal. Rocks, p. 11. 



procne, id., 1885 ; 3d Rept. Comm. Fossil Phyllopoda Pal. Rocks, p. 3. 



procne, Hall & Clarke, 1888 ; Pal. New York, vol. 7, p. 201, pi. 35, 

 figs. 25-27. 



procne, Etheridge, Woodward, & Jones, 

 1888; 6th Rept. Comm. Fossil Phyllo- 

 poda Pal. Rocks, p. 9. 

 Dithyrocaris (Scouler, 1843, MSS.), Port- 

 lock; Rept. Geol. Londonderry, p. 313. 



Diagnosis. — Carapace subquadrate in out- 

 line, bivalvular, the valves being con- ' 

 nected by a simple, straight hinge-line, 

 and gaping at the anterior extremity 

 forming the rostral cleft. Rostrum un- 

 known, each valve bearing a single 

 gently curved carina. Optic node gener- 

 ally conspicuous. Abdomen composed 

 of ? segments of which one is naked. 

 Post-abdomen consisting of caudal plate 

 aud three caudal spines. 

 Belli, Woodward, 1870 ; Geol. Mag., Dec. 

 2, vol. 8, p. 106, pi. 3, figs. Devonian. 

 Belli, Etheridge, Woodward, & Jones, 1887; 

 5th Rept. Comm. Fossil Phyllopoda Pal. 

 Rocks, p. 6. 



