l68 THE APPENDAGES, ANATOMY, AND RELATIONS OF TRILOBITES. 
Reed, F. R. C. 
1916. — The genus Trinucleus. Pt. 4. Geol. Mag., dec. 6, vol. 3, pp. 121, 122. 
Richter, R. 
1848. — Bitrag zur Palseontologie des Thuringer Waldes. Dresden and Leipzig. 
RlNGUEBERG, E. N. S. 
1886. — A trilobite track illustrating one mode of progression of the trilobites. Proc. 
Amer. Assoc. Adv. Sen, vol. 35, p. 228 (abstract only). 
Ruedemann, R. 
1916. — The presence of a median eye in trilobites. Bull. New York State Mus., No. 189. 
pp. 127-143, pis. 34-36. 
Schlotheim, E. F. von. 
1823. — Nachtrage zur Petrefactenkunde, II. Gotha. 
Six, Achille. 
I gg 4 _ — Les appendices des trilobites d'apres M. Ch. D. Walcott. Ann. Soc. Geol. du 
Nord, vol. 11, pp. 228-236. 
Spencer, W. K. 
I go3. — The hypostomic eyes of trilobites. Geol. Mag., dec. 4, vol. 10, pp. 489-492. 
Staff, Hans v., and Reck, Hans. 
191 1. — Ueber die Lebensweise der Trilobiten. Fine entwicklungsmechanische Studie. 
Gesell. naturforsch. Freunde, Sitzb, pp. 130-146, figs. 1-20. 
Sternberg, K. M. 
jg-^o. — Ueber die Gliederung und die Fiisse der Trilobiten. Isis (Encycl. Zeitung), Oken, 
p. 516, pi. 5, figs.1-3. 
Stokes, C. 
1822. — On a trilobite from Lake Huron. Trans. Geol. Soc, London, ser. 2, vol. 1, p. ■ 
208, pi. 27. 
Swinnerton, H. H. 
1919. — The facial suture of the trilobite. Geol. Mag., dec. 6, vol. 6, pp. 103-110. 
Tornquist, S. L. 
1896 A. — On the appendages of trilobites. Ibid., dec. 4, vol. 3, p. 142. 
1896 B. — Linnaeus on the appendages of trilobites. Ibid., pp. 567-569. 
Tothill, J. D. 
igi6. — The ancestry of insects, with particular reference to chilopods and trilobites. Amer. 
Jour. Sci. (4), vol. 42, pp. 373-3 8 3. text figs- I ' 8 - 
Troedsson, G. T. 
1918. — Om skanes Brachiopodskiffer. Lunds Universitets Arsskrift, n. f., Avd. 2, Bd. 15, 
Nr. 3, pp. 57-67, pi. 1, figs. 19-24. 
Valiant, W. S. 
1901. — Appendaged trilobites. The Mineral Collector, vol. 8, No. 7, pp. 105-112. 
Volborth, A. von. 
1858. — Ueber die Bewegungs-Organe der Trilobiten. Verhandl. russ. k. mineral. Gesell. 
zu St. Petersburg, 1857-1858, p. 168. 
1863. — Ueber die mit glatten Rumpfgliedern versehenen russischen Trilobiten, nebst einem 
