NArXILlD-E. 
45 
tion of Trocholites planorhifonms that he had examined Conrad’s 
original specimen in the cabinet of the Academy of Natural Sciences 
at Philadelphia, before coming to the conclusion that his specimens 
were identical with Conrad’s. Conrad gives no figure of the section of 
the whorls of his species by which the relations of the two diameters 
could be seen ; but his figure of the shell (viewed laterally) is 
excellent in all respects, and it differs in no way (except perhaps 
that the umbilicus is a little deeper) from Hall’s figure (Pal. New 
York, vol. i. pi. Ixxxiv. fig. 3 a). It should be added that both 
Hall’s and Conrad’s specimens, here spoken of, came from precisely 
the same locality, viz. near Grimbsy, Canada West, and were col- 
lected by the same individual, a Mr. Ashmead of Philadelphia. 
Trocholites undosus, J. de C. Sowerby, sp. 
1839. Nautilus undosus, J. de C. Sowerby, in Murchison’s ‘ Sil. Syst.’ 
pt. ii. p. 642, pi. xxii. f. 17. 
1848. Lituites undosus, Salter, Mem. Geol. Surv. vol. ii. pt. i. p. 352. 
1849. Lituites undosus, d’Orbigny, Prodr. de Paleont. Stratigr. vol. i. 
1852. Trocholites anffuiformis, M‘Coy, British Pal. Foss. fasc. ii. p. 323, 
pi. i. L f. 26. 
1854. Lituites angulatus, Saemann, Ueber die Nautiliden, in Paheonto- 
graphica, Band iii. p. 166, tab. xxi. ff, 1 a-d. 
1855. Lituites anguiformis, Salter, in Sedgwick k McCoy’s British Pal. 
Foss., Appendix A, p. viii, pi. i. l. f. 26. 
1860. Clymenia rarospira (pars), Eichwald, Lethaea Rossica, vol. i. 
Seconde Section de I’ancienne Periode, p. 1302, pi. l. ft*. 1 a,h, k 
3 a-c ; not ft’. 2 a, b,Q a-c. 
1861. LAtuites antiquissimus , Ferd. Roeraer, Die Fossile Fauna der 
Silurischen Diliivial-Geschiebe von Sadewitz, p. 62, Taf. vi. ff. 2, 
b, c, d, e-, not ff. 2 a,f, g. (Not Clymenia antiquissima, Eichw.) 
1879. Lituites undosus, Kjerulf, Udsigt overdet sydlige Norges geologi. 
Atlas, pi. xvi. 
1880. Discoceras convolvens, Angelin & Lindstrom, Fragmenta Silurica, 
p. 10, tab. xvi. f. 3. (Not Lituites convolvens, Ilisinger.) 
1880. Lituites undosus, Kjerulf & Gurlt, Die Geologie des siidlich. und 
mittl. Norwegen, p. 68. 
1882. Trochocei'as undosum, Blake, British Foss. Ceph. pt. i. p. 226, 
pi. XXX. AT. 5, 5 ; not f. 6. 
1882. Nautilus {Trocholites) anguiformis, Blake, ibid. p. 213, pi. xxviii. 
ff. 2, 2 a. 
1883. Trocholites angulatus, Hyatt, Proc. Boston Soc. Nat. Hist, 
vol. xxii. p. 267. 
Sp. Char. Shell discoid, consisting of 3 or 4 volutions, which 
are all visible ; each whorl is slightly indented on the concave side, 
