856 CALIFORNIA ACADEMY OF SCIENCES. 



SHUMARDIA. SOLENOPLEURA. 



The head of Shumardia gramilosa diflfers from Baitus pusillus in 

 having a groove, which runs from the anterior front of the gla- 

 bella to the frontal margin of the head, a characteristic of some 

 species of Agnostidm (vid. Brogger, Sil. Etagen 2 und 3, pi. 1, 

 fig. 10). 

 Mr. Billings remarks that "in some specimens this furrow has at 

 the bottom a small triangular tubercle, giving the glabella the 

 appearance of having a projecting angular process in the middle 

 of its front." I am more inclined to view this triangular tubercle 

 as a point of attachment for the muscles of the jaws, and not as 

 a process for the attichment of antenuse. 

 Mr. E. Billings in the same book gives a description of a second 

 species, which he calls Shumardia glacialis, figured p. 283, fig. 

 270. The species is represented with three glabella furrows, and 

 should not be included in the genus Shumardia. 

 If these forms are not embryonic, I would advocate the acceptance 

 of Shumardia amongst the Atjnostidoi for such species as Shu- 

 mardia granulosa Bill, and Baitus pusillus Sars to replace the 

 later generic term of Conophrys Call. 



SoLENOPLKURA Aug., 1854; Palffiont. Scand., p. 26. Type, Solenopleura 

 holometopa Aug. Diagnosis: Glabella prominent, with three dis- 

 tinct furrows; fixed cheeks, elevated especially in the middle; 

 front limb convex; occipital ring bearing a tubercle; genal angles 

 pointed; thorax, pleurae bluntly rounded; pygidium small with 

 few segments; surface of shell granulated with or without scat- 

 tered tubercles. 



ACADIA Whiteaves, 1885; Trans. Royal Soc. Canada, vol. 3, p. 76, pi. 



7, fig. 15. Porter's Stream, N. B. Taconio. 



— — ACADIA Whiteaves, 1887; Trans. Royal Soc. Canada, vol. 4, p. 157, 

 pi. 2, figs. 5 a, b, c. 



ACADIA var. ELONGATA Matt., 1887; idem., p. 159, pi. 1, fig. 6. 



BOMBIFRONS Matt., 1886; Trans. Royal Soc. Canada, vol. 2, p. 156, 



figs. 5, 5 a-b. Topsail Head, Conception Bay, N. F. Taconic. 



BOMBIFRONS Wal., 1890; 10th Rep. U. S. Geol. Survey, p. 656, pi. 98, 



figs. 5, 5 a-b. Olenellus zone. 



COMMUNIS Bill., 1874; Pal. Foss., vol. 2, p. 72. Chapel Arm, Trinity 



Bay. 



COMMUNIS Matt., 1886; Trans. Royal Soc. Canada, vol. 2, p. 155, figs. 



4, 4 a, b. 



NANA Ford, 1878; Am. Jour. Sci., 3d series, vol, 15, p. 126. Troy, 



N. Y. Taconic. 



NANA Wal., 1866; Bull. U. S. Geol. Survey, No. 30, p. 214, pi. 27, fig. 3. 



•?NANA Wal., 1887; Am. Jour. Sci., 3d series, vol. 34, p. 196, pi. 1. 



figs. 1, 1 d. 



