766 CAMBRIAN BRACHIOPODA. 



Spiriferaf lenticularis (Wahlenberg), von Buch, 1834, Physikal. Abhandl. K. Akad. Wiss. Berlin, p. 48, PL I, figs. 

 13 and 14. (Described in German; see Matthew, 1892, p. 47, for translation.) 



Atrypa? lenticularis (Walilenberg) Hisingee, 1837, Lethsea Svecica, p. 76. (Not seen.) 



Atrypa lenticularis (Wahlenberg), Kjbrulp, 1857, Geologie des sudlichen Norwegens, p. 92. (Locality mentioned in 

 German.) 



Atrypa lenticularis (Walilenberg), Kjerulf, 1865, Veiviser ved Geologiske Excursioner i Christiania Omegn, p. 1, 

 and figs. 7a-d, p. 3. (Mentioned and locality given in Norwegian.) 



OrtMs lenticularis (Wahlenberg), Salter, 1866, Mem. Geol. Survey Great Britain, vol. 3, p. 339, PI. IV", figs. 8-10. 

 (Described and discussed; see Matthew, 1892, p. 47, for copy.) 



Orthis lenticularis (Wahlenberg), Davidson, 1868, Geol. Mag., vol. 5, p. 314, PL XVI, figs. 20-22. (Occurrence men- 

 tioned and new localities given.) 



Orthis lenticularis (Wahlenberg), Davidson, 1869, British Fossil Brachiopoda, vol. 3, pt. 7, No. 3, pp. 230-232, PI. 



XXXIII, figs. 22-28. (Described and discussed, copying Wahlenberg's original description in Latin, 1821, 



. p. 66. Figs. 22, 23 and 24, and 25 are copied from Salter, 1866, PL IV, figs. 9a, 9b, and 9c, respectively; figs. 



28 and 28a are copied from Davidson, 1868, PI. XVI, figs. 22 and 22a; and figs. 26, 26a-b are redrawn from the 



specimen figured by Davidson, 1868, PL XVI, figs. 21 and 21a.) 



OrtMs lenticularis (Wahlenberg)?, Kayser, 1876, Beitrage zur Geologie und Palseontologie der argentinischen Repub- 

 lik, vol. 2, Paleontologischen Theil, Abth. 1, p. 9, PL I, figs. 11 and 12. (Characterized and discussed in 

 German; see pp. 767-768 for translation.) 



Orthis STp.; Kayser, 1876, idem, p. 9, PL I, fig. 13. (Characterized in German; see p. 768 for translation.) 



Orthis lenticularis (Wahlenberg), Roemer, 1876, Lethroa geognostica, pt. 1, Lethaea palaeozoica. Atlas, PL II, figs. 4a-c. 

 (No text reference. Fig. 4a is copied from Salter, 1866, PL IV, fig. 9a; figs. 4b and 4c are copied from David- 

 son, 1869, PL XXXIII, figs. 26b and 26a, respectively.) 



Atrypa lenticularis (Wahlenberg), Kjerulf, 1879, Sydlige Norges Geologi, atlas, PL XIII. (Gives position in vertical 

 section.) 



Orthis lenticularis (Wahlenberg), Salter and Etheridge, 1881, Mem. Geol. Survey Great Britain, vol. 3, 2d ed., pp. 

 544-545, PL IV, figs. 8-10. (Text and figures copied from Salter, 1866, p. 339, PL IV, figs. 8-10.) 



Orthis lenticularis (Wahlenberg), Brogger, 1882, Die silurischen Etagen 2 und 3, p. 48. (Specimens from new locali- 

 ties discussed in German.) 



Orthis lenticularis (Wahlenberg), Roemer, 1885, Paleontologische Abhandlungen von Dames und Kayser, Bd. 2, Hft. 

 5, pp. 33-34 (280-281), PL I (XXIV), figs. 9a-c. (Occurrences of the species discussed in German. Pig. 9a is 

 copied from Salter, 1866, PL IV, fig. 9a; figs. 9b and 9c are copied from Davidson, 1869, PL XXXIII, figs. 26b 

 and 26a, respectively.) 



Orthis lenticularis (Wahlenberg), Matthew, 1892, Trans. Roy. Soc. Canada for 1891, vol. 9, sec. 4, No. 5, pp. 46^8, 

 PL XII, figs. 9a-d. (Gives original and translation of Wahlenberg, 1821, p. 66, translations of Dalman, 1828, 

 p. 132, and von Buch, 1834, p. 48, and copy of Salter, 1866, p. 339, and describes and discusses species. Speci- 

 mens from Matthew's material are figured in this monograph, PL XCVIII, figs. 3, 3a-b, but as far as can be 

 determined none of these specimens were figured by Matthew, 1892, PL XII, figs. 9a-d.) 



Orthis lenticularis strophomenoides Matthew, 1892, idem, p. 49, PL XII, figs. 12a-b. (Characterized and discussed 

 as a new variety. The specimens represented by PL XCVIII, figs. Ic and 2b, of this monograph, are typical of 

 this proposed variety, but they are drawn from material in the collections of the United States National Museum, 

 and are not the type specimens.) 



Orthis lenticularis (Wahlenberg), Matthew, 1903, Geol. Survey Canada, Rept. Cambrian Rocks Cape Breton, pp. 

 213-216, PL XVII, figs. la-d-. (Text and figures copied from Matthew, 1892, pp. 46^8, PL XII, figs. 9a-d.) 



Orthis lenticularis strophomenoides Matthew, 1903, idem, p. 217, PL XVII, figs. 4a-b. (Characterized. Figs. 4a-b 

 are copied from Matthew, 1892, PL XII, figs. 12a-b, respectively.) 



Orthis {Orusia) lenticularis (Wahlenberg), Walcott, 1905, Proc. U. S. Nat. Mus., vol. 28, pp. 273-276. (Described 

 and discussed essentially as below, giving translation of Kayser's references, 1876, p. 9. 



Matthew [1892, pp. 46-48], in his excellent review of the descriptions of this species, gives 

 a translation of Wahlenberg's original description, together with the I^atin; also the descrip- 

 tions of Dalman [1828, p. 132], von Buch [1834^ p. 48], and Salter [1866, p. 339]. 



He calls attention [1892, p. 47] to the fact that if the reader will compare the several descrip- 

 tions of this species by the authorities named he will be surprised at the diversity they exlaibit. 

 This diversity, Matthew thinks, is due partly to the imperfect descriptions of the earlier writers, 

 but chiefly to the remarkable variability of the species. Matthew recognizes the species in the 

 Upper Cambrian, near St. John, New Brunswick, and has also distinguished three varieties. 

 Through his kindness I had the opportunity of studying the types of the varieties. 



Through M. Schmalensee, a collector in the Geological Survey of Sweden, I secured a large 

 and fine series of this species from thin bands of limestone in the Olenus and alum shales on 

 Oeland Island and at Hunneberg. I also collected a quantity of the shells in the Upper Cam- 

 brian of Manuels Brook, Newfoundland. From this material an attempt has been made to 



