580 CAJMBRIAN BRACHIOPODA. 



short, rudimentary, and without well-defined pseudodeltidium. Interior of ventral valve with 

 median septum between the central and posterolateral muscle scars. 



Observations. — The short cardinal areas of the valves leave a broad open space between 

 them for the passage of the pedicle. The areas are more than reflected posterior margins of 

 the valves, as they have transverse lines of growth and a suggestion of a pseudodeltidium. 

 These features are more rudimentary than in Micromitra. Kutorgina includes the larger cal- 

 careous shells, and Micromitra the somewhat more specialized, smaller, corneous shells. The 

 exterior form of the valves of Kutorgina suggest Nisusia festinata (Billings), with which the 

 type species, K. cingulata (Billings), is associated in Vermont and at Bic Harbor. 



The genus was named in honor of Kutorga. 



Kutorgina cingulata (Billings). 

 Text figures 3, page 299; 8, page 299; 50A-C, page 581; Plate V, figures 1, la-s. 



Oholella {Kutorgina) cingulata Billings (in part), 1861, Geol. Survey Canada, Paleozoic Fossils, vol. 1, pp. 8-9, figs. 8 

 and 10 (not fig. 9). (Described as a new species. Fig. 9 is that of a specimen now referred to Rustella edsoni.) 



Obolella {Kutorgina) cingulata Billings (in part), 1861, Report on the Geology of Vermont, vol. 2, p. 948, figs. 347 and 

 349 (not fig. 348). (Text and figures copied from Billings, 1861b, p. 9, figs. 8 and 10, p. 8. Pig. 348 is that of a 

 specimen now referred to Rustella edsoni.) 



Obolella {Kutorgina) cingulata Billings (in part), 1862, Report on the Economic Geology of Vermont, by Hager, p. 220, 

 figs. 347 and 349 (not fig. 348). (Text and figures copied from preceding reference. Fig. 348 is that of a speci- 

 men now referred to Rustella edsoni.) 



Obolella cingulata Billings, 1863, Geol. Survey Canada, Fifteenth Rept. Progress, p. 284, figs. 287a and 287b (not fig. 



' 287c). (No text reference. Figs. 287a and 287b are copied from Billings, 1861b, figs. 8 and 10, p. 8. Fig. 



287c represents a specimen now referred to Rustella edsoni.) 



Kutorgina cingulata (Billings), Walcott (in part), 1886, Bull. U. S. Geol. Survey No. 30, pp. 102-104, PI. IX, figs. 1, 

 la-f (not figs. Ig and 111). (Original description, Billings, 1861b, p. 9, copied and species described and dis- 

 cussed. The specimens represented by figs. 1, la-f are redrawn in this monograph, PI. V, figs. Ic, lb. Id, la, 1, 

 li, and Ih, respectively. Specimens referred to Rustella edsoni are mentioned on p. 103 and are figured, PI. IX, 

 figs. Ig and Ih.) 



Kutorgina cingulata {Billinga), Beecher, 1891, Am. Jour. Sci., 3d ser., vol. 41, footnote, pp. 345-346. (Discusses 

 generic relations.) 



Kutorgina cingulata (Billings), Walcott, 1891, Tenth Ann. Rept. U. S. Geol. Survey, p. 609, PI. LXIX, figs. 1, la-f 

 (not figs. Ig and Ih). (Mentioned. Figs. 1, la-f are copied from Walcott, 18S6b, PI. IX, figs. 1, la-f. Figs. 

 Ig and Ih represent specimens now referred to Rustella edsoni.) 



Kutorgina cingulata (Billings), Hall and Clarke, 1892, Eleventh Ann. Rept. State Geologist New York for 1891, 

 PI. IV, figs. 11-13. (No text reference.) 



Kutorgina cingulata (Billings), Hall and Clarke, 1892, Nat. Hist. New York, Paleontology, vol. 8, pt. 1, p. 92, figs. 

 47-49; PI. IV, figs. 10-17. (Mentioned in discussing genus. Figs. 47-49 are copied from Walcott, 1886b, 

 PI. IX, figs, lb, la, and If, respectively. Figs. 13, 14, and 17 are copied from figs. 11-13 of the preceding 

 reference.) 



Kutorgina cingulata (Billings), Frech, 1897, Additional plates inserted in 1897 in Lethsea geognostica, pt. 1, Lethaea 

 palseozoica, atlas, 1876, PL I a, figs. 6a-b. (No text reference. Figs. 6a-b are copied from Walcott, 1886b, 

 PI. IX, figs, la and 1, respectively.) 



Kutorgina cingulata (Billings), von Toll, 1899, M6m. Acad. imp. sci. St.-P6tersbourg, 8th ser., vol. 8, No. 10, pp. 

 26-27, PI. I, fig. 28. (Described and discussed in German.) 



Kutorgina cingulata Billings, Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 308-309. (Described and discussed 

 essentially as below, with the e.xception of the notes and figures on the shell structure.) 



Kutorgina cingulata von Toll, Walcott, 1905, idem, p. 309. (Species and locality mentioned.) 



Kutorgina cingulata (Billings), Grabau and Shimer, 1907, North American Index Fossils, vol. 1, p. 209, fig. 246. 

 (Described. The three figures of fig. 246 are copied from Walcott, 1886b, PL IX, figs. 1, la, and lb.) 



General form transversely or longitudinally oval; biconvex, with the ventral much more 

 convex than the dorsal valve. Surface marked by concentric lines and ridges of growth and 

 the edges by imbricating lamellae of growth. Shell substance calcareous and fibrous. The shell 

 is formed of a tliin, dark, compact outer layer and a thick, laminated, calcareous inner layer. It 

 is possible that the tliin outer layer is chitinous, but it does not appear to be so. 



The L'Anse au Loup and Bic Harbor shells average about 15 mm. long by 17 mm. in width. 

 At the locality near Swanton, Vermont, ventral valves occur 24 mm. in length and 30 mm. in 

 width, and one large dorsal valve is 20 mm. in length with a width of 30 mm. 



