OLENELLUS AND OTHER GENERA OF MESONACID^ 265 



Barrandia vermontana Hall, i860. Thirteenth Ann. Rept. New York State 

 Cab. Nat. Hist, p. 117, text figure. (Discussed. The figure is copied 

 from Hall, 1859, fig. 2, p. 60.) 



Paradoxides vermonti Emmons, i860, Manual of Geology, 2d ed., p. 280, 

 note A. (Note on the stratigraphic position of the species.) 



Paradoxides vermontana Barrande, 1861, Bull. Soc. Geol. de France, 2d 

 ser.. Vol. 18, pp. 277-278. pi. 5, fig. 8. (Translates into French the 

 description given by Hall [1859, pp. 60-61] and copies Hall's outline 

 figure [1859, fig. 2, p. 60].) 



? Paradoxides vermontana (Hall), Billings, 1861, Geol. Survey Canada, 

 Paleozoic Fossils, p. 11. (Mentions presence of heads representing 

 this species at Anse au Loup. In view of the close similarity between 

 the heads of several of the forms now referred to the different genera 

 of the Mesonacidse the occurrence of this species at the locality men- 

 tioned must be regarded as doubtful.) 



Barrandia vermontana Hall (in part), 1861, Report on the Geology ot 

 Vermont, Vol. i, p. 370, first 6 paragraphs. (Copies the paragraph 

 given by Hall [i860, p. 117] and describes the species. The text 

 includes reference to figures given by Hall [1862, pi. 13] which are 

 referred in this paper to Paedemnias transit ans.) 



Barrandia vermontana Hall (in part), 1862, Report on the Geology of 

 Vermont, Vol. 2, pi. 13, fig. 2 (not fi.gs. 4 and 5, referred in this paper 

 to Paedeumias transitans). (Figure 2 is copied from Hall, i860, text 

 figure, p. 117; figures 4 and 5 appear to represent forms more like 

 Paedeumias transitans than Mesonacis vermontana) . 



Olenelhis vermontana Hall, 1862, Fifteenth Ann. Rept. New York State 

 Cab. Nat. Hist, p. 114. (Generic name Olenellus proposed.) 



Olenelhis vermontana Billing?, 1865, Geol. Survey Canada, Paleozoic 

 Fossils, Vol. I, p. II. (Reprinted from Billings, i86ia, p. 11, substi- 

 tuting Olenellus for Paradoxides.) 



Olenellus vermontanus Ford, 1881, American Journ. Sci., 3d ser.. Vol. 22, 

 fig. 13, p. 258. (Figure 13 is copied from Hall, 1859, fig. 2, p. 60.) 



Not Olenellus vermontana Whitfield, 1884, Bull. American Mus. Nat. 

 Hist, Vol. I, No. 5, pp. 152-153, pi. 15, figs. 2-4. (Referred in this 

 paper to Paedeumias transitans.) 



Mesonacis vermontana Walcott, 1885, American Journ. Sci., 3d ser.. Vol. 

 29, pp. 328-330, figs. I and 2, p. 329. (Discussed. Figures i and 2 are 

 outline drawings of the specimen figured in this paper, pi. 26, figs, i 

 and 2.) 



Mesonacis vermontana (Hall), Walcott, 1886, Bull. U. S. Geol. Survey, 

 No. 30, pp. 158-162, pi. 24, figs. I, la-b. (Copies the original description 

 given by Flail, 1859, pp. 60-61, and describes and discusses the species. 

 Figure i is copied from Hall, 1859, fig. 2, p. 60; and figures la and ib 

 are drawn from the specimen figured by Walcott, 1885, text figs, i and 

 2, p. 329. This specimen is the one illustrated in this paper, pi. 26, 

 figs. I and 2.) 



