776 PBOCEEDINGS OF THE NATIONAL MUSEUM. vol.xxii. 



(Group of Quadrula laohrymosa.) 



Sliell quadrate or rhomboid, generally with a sharp, well-developed 

 posterior ridge, iu front of which is a wide, shallow, radial excavation; 

 base incurved, posterior end sharply truncate, generally slightly bian- 

 gular below, high and distinctly angled behind the ligament; posterior 

 tubercles often iu somewhat radiating rows; earlier beak sculpture 

 consisting of ridges nearly parallel with the growth lines, but later on 

 becoming doubly looped and blending into the general sculpture of the 

 shell; eiDidermis smooth; pseudocardinals strong; laterals straight; 

 nacre white. 



Animal with all four gills used as a marsupium throughout, inner 

 much the larger, free from the abdominal sac nearly or quite their whole 

 length ; palpi very large; branchial opening generally having clustered, 

 often branching papillae; anal opening smooth; superanal opening 

 closed below. 



t QUADRULA ASPER Lea. 



* Unio asper Lea, Tr. Am. Phil. Soc, IV, 1831, p. 85, pi. ix, fig. 15; "" Obs., I, 1834, 



p. 95, pi. IX, fig. 15.— * Conrad, Xew F. W. Shells, 1834, p. 67.— *Hanley, 

 Test. Moll., 1842, p. 179 ; * Biv. Shells, 1843, p. 179, pi. xxii, fig. 37.—" Catlow 

 and Reeve, Conch. Nom., 1845, p. 56, — * Conrad, Pr. Ac. N. Sci. Phila., VI, 

 1853, p. 245.— *H. and A.Adams, Gen. Rec. Moll., II, 1857, p.497.— *Chenu, 

 111. Conch., 1858, pi. xv, figs, 4, 4a, 46; * Manual, 1859, II, p. 142, fig. 695.— 



* Reeve, Conch, Icon., XVI, 1864, pi. v, fig. 18.— *B. H. Wright, Check List, 

 1888. 



* Margarita {Unio) asper Lea, Syn., 1836, p. 15; 1838, p. 15. 

 *Margaron (Unio) asper Lea, Syn., 1852, p. 22; 1870, p. 33. 



* Unio nobilis Conrad, Jl. Ac. N. Sci. Phila., II, 1854, p. 297, pi. xxvii, figs. 2, 3. 



* Unio turgidns Reeve, Conch. Icon., XVI, 1864, j)l. iii, fig. 10. 



^ Unio apiculatus var. asjyer P^.tel, Conch. Sam., Ill, 1890, p. 144. 



Streams flowing into the Gulf of Mexico from Alabama west to cen- 

 tral Texas, and northward to the Verdigris Eiver, Kansas. 



tQUADRULA LACHRYMOSA Lea. 



Unio lachrymosus Lea, Tr. Am. Phil. Soc, III, 1828, p. 272, pi. vi, fig. 8; ' Obs., I, 

 1834, p. 14, pi. VI, fig. 8.—* Short and Eaton, Transylvania Jl., 1831, p. 76.— 

 *Ferussac, Guer. Mag., 1835, p. 27.— ^Hanley, Test. Moll., 1842, p. 177; 

 *Biv. Shells, 1843, p. 177, pi. xx, fig. 38.—* Catlow and Reeve, Conch. Nom., 

 1845, p. 60.— *H. and A. Adams, Gen. Rec. Moll., II, 1857, p. 497.--*Chenu, 

 111. Conch., 1858, pi. xv, figs. 6, 6a, 6h; Manual, 1849, II, p. 142, fig. 6;18.— 



* Reeve, Conch. Icon., XVI, 1864, pi. ix, fig. 33.— ^B. H. Wright, Check 

 List, 1888.— *P.ETEL, Conch. Sam., III,. 1890, p. 156. 



* Margarita ( Unio) lachrymosus Lea, Syu., 1836, p. 14; 1838, p. 15. 



* Margaron ( Unio) lachrymosus Lea, Syn., 1852, p. 21; 1870, p. 32. 



* Unio lachrymosus Kuster, Conch. Cab., 1854, p. 70, pi. xvii, fig. 3. 



'Published as a separate in 1827. 1 have not seen this. Title from Sabin's Biblio- 

 theca America. 



