NO. 1205. SYJSrOPSIS OF TRE NAIADES— SIMFSOK 769 



37.— ^Reeve,Codc1i. Icon., XVI, 1864, pi. v, fig. 20.— *B.H. Wright, Check 

 List, 1888. 

 * Margaron ( Unio) ellioitii Lea, Syn., 1870, p. 29. 



Southern Georgia to Texas. 



tQUADRULA UNDULATA Barnes. 



^Uiiio iindidatus Barnes, Am. JL Sci., VI, 1823, p. 120, pi. ii. — ^Hildreth, Am. 

 Jl. Sci., XIV, 1828, p. 279.—* Hanley, Test. Moll., 1842, p. 175 ; * Biv. Shells, 

 1843, p. 175, pi. XX, fig. 26. — *Catlow and Eeeve, Conch. Nom., 1845, p. 

 65.—* Chenu, Bib. Conch., 1st ser., Ill, 1845, p. 24, pi. v, figs. 1, la.—* H. and 

 A. Adams, Gen. Eec. Moll., II, 1857, p. 495. — * Chexu, Manual, 1859, II, p. 143, 

 fig. 704. — *SowERBy, Conch. Icon., XVI, 1868, pi. lxxvi, fig. 399. — * Calk- 

 ins, Pr. Ottawa Acad. Sci., 1874, p. 45.—* B. H. Wright, Check List, 1888. 



^Margarita {Unio) undulatus Lea, Syn., 1836, p. 12; 1838, p. 14. 



*Margaron ( JJnio) undulatus Lea, Syn., 1852, p. 20; 1870, p. 29. 



*M\ja undulata Eaton, Zool. Text-Book, 1826, p. 219. 



* Pnio «H(Z»Z« to Valenciennes, Eec. Obs. Zool. Auat., II, 1833, p. 229, pi. liv, 

 figs. 3, oa,3h. — *Deshayes, Tr. Elem. Conch., 1839, p. 19, pi. xxx, figs. 8, 9. 



*Quadrula undulata Baker, Moll. Chicago, Pt. I, 1898, p. 82, pi. xxii, figs. 1, 2; 

 xii, fig. 1. 



*Unio costatus Say, Am. Conch., VI, 1834. — * Conrad, New F. W. Shells, 1834, 

 p. 68.— *Ferussac, Guer. Mag., 1835, p. 27. — * Conrad, Mouog., 11,1836, 

 p. 17, pi. VII. — * Kuster, Conch. Cab., 1852, p. 54, pi. xi, fig. 4. — * Eeeve, 

 Conch. Icon., XVI, 1864, pi. iv, fig. 16. 



Tlectomerus costatus Conrad, Pr. Acad. N. Sci. Phila., VI, 1853, p. 260. 



*Unio jilicatus Kuster, Conch. Cab., 1856, p. 137, pi. xl, fig. 3. — * Chenu, 

 Manual, 1859, II, p. 143, fig. 706. 



"Unio atrocostatus Sowerby, Conch. Icon., XVI, 1868, pi. lxxvii, fig. 404. 



tQUADRULA UNDULATA var. LATECOSTATA Lea. 



""Unio latecostatus Lea, Pr. Am. Phil. Soc, IV, 1845, p. 163 ;i * Tr. Am. Phil. 

 See, X, 1848, p. 68, pi. i, fig. 2; * Obs., IV, 1848, p. 42, pi. i, fig. 2.—* Kuster, 

 Conch. Cab., 1861, p. 251, pi. lxxxiv, fig. 4. — *B. H. Wright, Check List, 



* Margaron ( Unio) laticostasus Lea, Syn., 1852, p. 21. 

 *Margaron {Unio) laticostatus Lea, Syn., 1870, p. 31. 



*Unio laticostatus H. and A. Adams, Gen. Eec. Moll., II, 18.57, p. 497. — *P/etel, 

 Conch. Sam., Ill, 1890, p. 156. 



tQUADRULA UNDULATA var. PILSBRYI Marsh. 



* Unio pilshryi Marsh, Nautilus, V, 1891, p. 1.-—* Pilsbry, Pr. Ac. N. Sci. Phila., 

 1892, p. 131, pi. VIII, figs. 7, 8; * Nautilus, VII, 1893, pi. i, figs. 7, 8.3 



1 More compressed and having finer, more delicate plications than the type. I 

 have traced it northward into Kansas, where it gradually assumes the ordinary form 

 of undulata. Occasional specimens are found in the Northern States which agree 

 very well with the typical latecostaia. 



■^I feel quite sure that this is only a peculiar variety of undulata. 



^A peculiar shell belonging to Mr. J. H. Ferriss, of Joliet, Illinois, from Lake Win- 

 nipeg, has been examined by the writer. It has unusually strong growth lines and 

 Is quite full in the ventral region, and has only the very faintest vestiges of plica- 

 tions below the lower part of the posterior ridge. I regard it as a smooth form of 

 Q. undulata, and if any considerable number of such specimens were found it might 

 be worthy of a varietal name, 



Proc. N. M. voi. xxii 49 



