268 CALIFORNIA ACADEMY OF SCIENCES. 



AGKAULOS. 



ArionelhiR OWEXI Meek and Haydeu; Pal. Upper Missouri, p. 9, figs. 



a, b, c, pi. 1, fig. 4. Kef erred by Walcott, 1884, Pal. Eureka 



Dist., Moii. U. S. Geol. Survey, vol. 8, p. 55, pi. 10, to Pty- 



chopctria oweni. 

 Arionellus (Bathyurus) PLAXUS Shuiii., 1861;. Am. Jour. Sci., 2d 



series, vol. 32, p. 219. Morgan's Creek, Burnet county, Texas. 



Taconic. 

 Arionellus PUSTULATUS Wai., 1877; Advanced sheets 31st Kep. New 



York State Mus. Nat. Hist., p. 15. Chazy, N. Y. 

 Arionellus PUSTULATUS Wai., 1877; 31st Eep. New York State Mus. 



Nat. Hist., p. 68. 

 Arionellus QUADRAXGULARIS Whit., 1884; Bull. Mus. Nat. Hist, New 



York, vol. 1, p. 147, pi. 14, fig. 8. Braintree, Mass. Taconic. 



QUADRAXGULARIS Wai., 1884; Bull. U. S. Geol. Survey, No. 10, p. 48, 



pi. 7, fig. 1. 



- REDPATHI Wai., 1891; 10th Eep. U. S. Geol. Survey, p. 654, fig. 69. 



St. Simoiids, Quebec. Taconic. 



SOCIALIS Bill., 1874; Pal. Foss., vol. 2, p. 71 fig. 40. Chapel Arm., 



Trinity Bay, N. F. Taconic. 



SOCIALIS Bill., 1882; Rep. of Progress Geol. Survey Newfoundland, 



p. 10, fig. 4. 



SOCIALIS Matt., 1886; Trans. Eoyal Soc. Canada, vol. 2, p. 151, fig. 1 



a-b. 



STRENUUS Bill., 1874; Pal. Foss., vol. 2, p. 71, fig. 41. Topsail Head 



and Brigus, Conception Bay. Taconic. 



STRENUUS Bill., 1882; Eep. of Progress Geol. Survey of Newfound- 



land, p. 10, fig. 5. 



- STREXUUS Matt., 1886; Trans. Eoyal Soc. Canada, vol. 2, p. 153, figs. 



3, 3 a-b. 



STRENUUS Wai., J891; 10th Eep. U. S. Survey, p. 655, pi. 96, figs. 1 a-c; 



also, var. nasutus, p. 654, pi. 97, figs. 2, 2 a-c. Olenellus zone. 

 Walcott refers Ptychoparia mucronatus S. & F. to this species. 

 Matthew uses the species for the type of the subgenus Strenuella, 

 Trans. Eoy. Soc. Canada, 1886, p. 154. 



subclavatus Bill. (See Ptychaspis subclavatus.) 



Arionellus (Bathyurus) TEXANUS Shum., 1861; Am. Jour. Sci., 2d 

 series, vol. 32, p. 218. Clear Creek, Burnet County, Texas. 



Taconic. 



Arionellus TRIPUXCTATUS Whitf., 1876; Eep. Eecoii. Upper Missouri, 

 p. 141, pi. 1, figs. 3-5. Moss Agate Springs near Camp Baker, 

 Montana. Taconic. 



? WHITFIELDIANUS Matt., 1887; Trans. Eoy. Soc. Canada, vol. 5, p. 130, 



pi. 1, figs. 1, 1 a-f. 



