296 CONCHIFERA. 



Unio pictorum. Lam. Hist. vi. 77. ; Ency. Meth. 



t. 248. f. 4.; Drop. Moll t. 11. f. 4.; Rossm. 



Icon. t. 3. f. 71. a. b. ; Pfeiffer, i. t. 5. f. 9, 10. 



Unio rostratus. Pfeiffer, i. 114. t. 5. f. 8. ; Alder, 



Mag. Nat. Hist. ii. 

 Mysca pictorum. Turton, Bivalves, 245., Man. ed. 



1. f. 11. 



Unio elongatula. Pfeiffer, ii. 35. t. 8. f. 5, 6. 

 Inhab. slow rivers. 



125.2. UNIO Batavus. Dutch Union, (t. 2. f. 10.) 

 Shell oblong, rounded at each end, with the beak 

 rugged and warty. 



Mya Batava. Wood, Conch. 403. t. 19. f. 1, 2. 

 Mysca Batava. Turton, Man. ed. 1. 20. f. 10. (cop. 



of Wood). 

 Mya pictorum. Montagu, T. B. 36. ; Donov. B. 



S. t. 176. 



Inhab. " the river Kennet above Newbury." 

 Shell an inch long and two broad, greenish brown, 

 without contraction in the frout margin, by which it 

 is chiefly distinguished from Unio pictorum ; inside 

 dark bluish. I only know this shell from Dr. Tur- 

 ton's account. It appears by Wood's figure to have 

 been described from a worn shell, such as the Dutch 

 colours are sent in. I do not find any species like it 

 figured in any of the works on European shells. It is, 

 perhaps, a specimen of the former with the edges 

 filed. The figure is more like a young Alasmodon 

 in shape and colour; and this is the only Unionida 

 I know which is dark blue within. Mr. James D. 

 C. Sowerby informs me my suspicions are correct, and 

 that Wood's figure was taken from a Dutch specimen, 

 so that it is most probable this species is not British. 



