G90 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL.XXII. 



UNIO ELLIPSOIDEUS Locard. 



* Unio ellipnoidcits LOCARD, Arch. Mas. Lyou., Ill, 1883, p. 211, pi. xxi, ligs. 1-3. ' 



* WESTEKLUND, Fium. Pal., II, Pt. 7, 1890, p. 171. * P.KTKL, Conch. Sam., 



Ill, 1890, p. 151. 

 I'niu genezftMtknitit LOCAKU, Arch. Mus. Lyou., Ill, 1883, p. 213, pi. xxi, tigs. 



4-6. ^P^ETKL, Conch. Sam., Ill, 1890, p. 153. * WESTKRLUND, Faun. Pal., 



II, Pt. 7, 1890, p. 172. 

 I'liio jaubertl LUCAHU, Arch. Mus. Lyou., Ill, 1883, p. 248, pi. XXH, figs. 8-10. 



*1\KTEL, Couch. Sam., Ill, 1890, p. 155. * WESTERLUND, Faun. Pal., II, Pt. 



7, 1890, p. 176. 



t'nio :abiilonicu8 KOUKLT, Icon., hew ser., VI, 1893, p. 96, pi. CLXXIX, fig. 1129. 

 *Unio lortiti KOHELT, Icon., 1st sup., 1895, p. 14, pi. v, tig. 3. 

 I'n to kobelti ROLLK, Icon., 1st sup., 1895, p. 15, pi. vi. fig. 3. 



* Unio pietri KOHELT (part), Icon., 1st sup., 1895, p. 16, pi. vi, figs. 1, 2. 



* Uniajierodes KOBELT, Icon., 1st sup., 1895, p. 17, pi. vi, fig. 4. 



Lake Tiberias. 



tUNIO DELICATUS Lea.- 



* Unio delicatus LEA, Pr. Acad. N. Sci. Phila., VII, 1863, p. 189. Ml. AcaU. N. Sci. 



Phila., VI, 1866, p. 58, pi. xix, tig. 56. *Obs., XI, 1867, p. 62, pi. xix, fig. 

 56. * WESTERLUND, Fauu. Pal., II, Pt. 7, 1890, p. 178. *PJETEL, Couch. 

 Sain., Ill, 1890, p. 150. 

 *Marf/aron ( Unio) delicatus LKA, Syn., 1870, p. 42. 



Oroiites Kiver, Syria. 



(Group of Unio littoralis.) 



Shell rather solid, subiutiated, rounded rhomboid, with a faint pos- 

 terior ridge, usually slightly biangulate behind and often becoming 

 arcuate when old; beaks prominent and full; beak sculpture consisting 

 of numerous rather line, subparallel ridges or corrugations which are 

 sometimes a good deal broken up, and which extend well out on the 

 disk, but begin at the beaks as normal, somewhat coarse Unio sculpture, 

 sometimes with fine radial lines posteriorly; pseudocardinals rather 

 solid, subcompressed, smooth below ; laterals straight or slightly curved; 

 cavity of the beaks rather deep ; muscle scars distinct. 



I have never seen the soft parts, of any member of this group. 

 Quite a number of descriptions have been published of various nominal 

 species, most of which go into details as to the color of the different 

 parts, but do not give an atom of information as to real characters. 

 The animal is dark or highly colored, and seems to be gravid in sum- 

 mer, and no doubt carries the young in the outer gills alone. Gills 

 large, wider behind, inner the larger, especially in front; mantle thick- 

 ened at the edges; palpi very large, elliptical, rounded behind, hanging 

 at an angle of 45; branchial opening large, strongly fringed/' 



'I think this is a form of grelloisianns. Some forms of the latter are very much 

 like U. tlgridus Bourguignat, but he says that it has roughened beaks while those 

 of tigridis are always smooth. 



-I have only seen the type, a young shell, and its relations are doubtful. The 

 sharp, rather pustulous, beak sculpture, and the shining, yellowish epidermis are 

 like the i>ictorum group, but its form is peculiar. It may not come from Syria at all. 



:i From a figure in Mai. d'Algerie, II, pi. xix. 



