THE NATURAL HISTORY SURVEY. 2C>5 



1883. Illaenus (Bumastus} ioxus. Hall, Trans. Albany Inst., vol. 

 10, p. 76. 



Niagara: Waldron, Ind. 

 1890. Illaenus ioxus. Foerste, Proc. Bost. Soc. Nat. Hist., vol. 



24, p. 268, pi. 5, fig: 20. 



1901. Illaenus ioxus. van Ing., School of Mines Quart., vol. 23, 

 p. 35 (no description). 



Silurian: St. Clair Spring, Independence Co., Ark. 

 1901. Illaenus ioxus. Grabau, Bull. N. Y. St. Mu's., No. 45, vol. 

 9, p. 223, fig. 154* 



Rochester shale: Niagara, Lockport, etc., N. Y. 

 1904. Illaenus ioxus. Kindle, 28th Ann. Rep. Dep. Geol. and 

 Nat. Res. Indiana, p. 480, pi. 22, fig. 7; pi. 23, fig. -3. 



Niagara: Pendleton, Fishersburg, Helm's Mill and 



Connor's Mill, Ind. 

 1907. Illaenus ioxus. Weller, This Bulletin, p. 222, pi. 18, figs. 1-3. 



Niagaran: Joliet, 111. 



Illaenus madisonianus Whitf., see Illaenus niagarensis Whitf. 

 Illaenus niagarensis Whitf. 



1880. Illaenus niagarensis. Whitf., Ann. Rep. Wis. Geol. Surv., 

 for 1879, p. 68. 



Niagara : Wisconsin. 



1882. Illaenus madisonianus. Whitf., Geol. Wis., vol. 4, p. 307. 

 pi. 20, figs. 8-9. 



Niagara : Wisconsin. 



1885. Illaenus madisonianus. Foerste Bull. Sci. Lab. Den. tlniv., 

 vol. 1, p. 106, pi. 14, figs, la-lb, 2a-2b. 



Clinton: Dayton, Ohio. 



1887. Illaenus madisonianus. Foerste, Bull. Sci. Lab. Den. Univ., 

 vol. 2, p. 93, pi. 8, figs. 8, 9, 10, lOa. 



Clinton: Near Dayton, Ohio. 



1895. Illaenus madisonianus. Foerste, Geol. Surv. Ohio, vol. 7, 

 p. 526, pi. 26, figs. 1-2, varieties, pi. 27, figs. 7-10. 



Clinton: Ohio. 



1901. Illaenus madisonianus. van Ing., School of Mines Quart., 

 vol. 23, p. 35 (no description). 



Silurian: St. Clair Spring, Independence Co., Ark. 

 1907. Illaenus niagarensis. Weller, This Bulletin, p. 219, pi. 19, 

 figs. 7-11. 



Niagaran: Joliet and Lockport, 111. 

 Illaenus pterocephalus Whitf. 



1878. Illaenus pterocephalus. Whitf., Ann. Rep. Wis. Geol. Surv., 

 for 1877, p. 87. 



Niagara: Pewaukee, Wis. 



1882. Illaenus pterocephalus. Whitf., Geol. Wis., vol. 4., p. 309, 

 pi. 20, figs. 10-12. 



Niagara: Pewaukee, Wis. 

 Illaenus springfieldensis Meek. 



1873. Illaenus (Bumastus') -insignis ? Meek, Pal. Ohio, -vol. 1, p. 

 189, figs. A-B; pi. 15, figs. 5a-c. 

 Niagara: Springfield, Ohio. 



