NO. 1205. SYNOPSIS OF TIIK X.U.I DKS-SIMI'Slt \ . 7()1 



UNIO CALLOSUS Lea. 



I nin calloxH* LKA, 1'r. Am. Phil. S.c. II, 1841, p. 31; *Tr. Am. Phil. Hoc., VIII, 

 1842, p. 239, pi. xxin, fig. 51; * Obs., Ill, 1842, p. 77, pi. xxm, fig. 54. 

 * CUNUAD, Pr, Acad. Nat. Sci. Phila., VI, 1853, p. 246.* II. and A. ADAMS, Gen. 

 Rec. Moll., II, 1857, p. 492. "CiiENU, 111. Conch., 1858, pi. xxvi, figs. 4, 4a, 

 41. * B. H.WRIGHT, Check List, 1888. *P.KTEL, Conch. Sam., Ill, 1890, p. 147. 



* Manjaron ( Unio) callosns LEA, Syn., 1852, p. 33; 1870, p. 33. 



Said to come from the Ohio Canal below Columbus. I am sure that 

 the locality is wrong, and it appears to be a Mexican form. The type 

 is not in the Lea collection. 



UNIO MEXICANUS Philippi. 



/ 'niomexicanuisPmiAPPi, Zeits.fiir Mai., IV, 1847, p. 95. * PHILIPPI, Abbild. und 

 Beschr., Ill, 1849,-p. 110, pi. vi, fig. 3.'* KUSTER, Conch. Cab. Unio, 1862, p. 

 285, pi. xcv, fig. 7. *B. H.WRIGHT, Check List, 1888. ^P.ETEL, Couch. Sam., 

 Ill, 1890, p. 159. * FISCHER and CROSSK, Miss. Sci., Pt. 7, II, 1894, p. 593. 

 *" Margaron ( Unto) mexicanus LEA, Syn., 1870, p. 53. 



Mexico. 



(Group of Unio semigranosus.} 



Shell triangular rhomboid, solid, inflated, with a distinct posterior 

 ridge; beaks rather full, their sculpture consisting of numerous some- 

 what irregular corrugations which pass into the pustulous sculpture of 

 the shell; surface of the valves generally more or less sculptured with 

 chevron-shaped or zigzag ridges or corrugations, which often break into 

 pustules, the posterior slope bearing curved, radiating plications which 

 are likewise sometimes nodulous; epidermis dark, scarcely rayed ; pseu- 

 docardinals strong, radial, ragged; laterals heavy, obliquely striated; 

 beak cavities not deep, compressed; muscle scars well impressed; 

 nacre purple, with bronzy or coppery shades. 



Animal apparently not different from that of other related Uuios. 

 I have not seen any with the marsupium filled. 



fUNIO PLEXUS Conrad. 



* Margarita ( Unio) carbonarius LEA, Syn., 1836, p. 192; 1838, p. 17.- 



* Unio carbonarius LEA, Tr. Am. Phil. Soc., VI, 1838, p. 37, pi. XL, fig. 32; *Obs., II, 



1838, p. 37, pi. xi, fig. 32. *TR08CHEL,Arch. fur Naturg.,V, 1839, Pt. 2, p.236. 

 *HANLEY, Test. Moll., 1842, p. 184; *Biv. Shells, 1843, p. 184, pi. xxn, fig. 

 10. *CATLOW and REEVE, Conch. Nom., 1845, p. 57. *CHEXU, 111. Conch., 

 1858, pi. xxm. figs. 1, la, !&. *!\ETEL, Conch. Sam., Ill, 1890, p. 147. 

 Margarita ( Unio) pi infer us LEA, Syn., 1836, p. 13; 1838, p. 14. 



* I'nio pliciferus LEA, Tr. Am. Phil. Soc.,VI, 1838, p. 61, pi. xvn, fig. 53; *Obs., II, 



1838, p. 61, pi. xvn, fig. 53.* TROSCHEL, Arch, fur Naturg., V, 1839, Pt. 2, p. 



1 A miserable figure of some rhomboidal, rather compressed form, probably group- 

 ing with caUosus. 



2 The names carbonarius and pliciferus were published two years before I'nio plexus, 

 but were not accompanied by a description. Part X of the Mouography appeared 

 in May, 1838, and the transactions, containing Dr. Lea's description of carbonarius 

 June 15, according to Seudder. Dr. Lea places his carbonarius in the synonymy of 

 pliciferus, though the former comes first in his paper. 



