340 TESTACEOUS MOLLUSGA. 
greater) propriety have been located in Mactra; L. squamosa must 
be set apart as belonging to the excellent genus 
LEPTON, Turton. 
“Shell flat, nearly orbicular, equivalve, inequilateral, a little open 
at the sides. Hinge of one valve with a single tooth and a transverse 
linear lateral one each side; of the other valve with a cavity in the 
middle and a transverse deeply cloven lateral tooth each side, the seg- 
ments of which divaricate from the beak. Ligament internal.” 
L. squamosum (p. 28, as Lutraria s.), t.9, £47. See, too, L. faba- 
gella, Conrad (Am. Mar. C. t. 11, f. 3), L. nitidwn, Turton (Dith. Brit.) 
and L. Clarkia (Brit. Mol.). 
On Macrra (p. 28). Consult the monographs by Spengler (Skriv. 
Nat. vol. 5, pt. 2) and Reeve (Conch. Icon.). See, too, Zeit. Mal. 
1848, 1849, 1850, 1851, Wieg. Arch. 1837, Proc. Bost. vol. 3, 
Gould’s Pacific Shells, and J. Conch. vols. 3, 4. 
On Mactra lactea (p. 31), striatula (p. 29) and ovalina (p. 31). 
The first (described and delineated from Poli) is only a variety of 
M. subtruncata (p. 382); the second is not the species so named by 
Linneus (Ipsa Lin.) and must consequently assume the earliest 
correct published name WM. alata (Spengler, Skr. Nat. Selsk. 1802); 
the third, according to D’Orbigny, is identical with M. fragilis of 
Chemnitz (Ch. f. 235). 
Mactra maculosa, p. 29, t. 11, f. 27... MM. fasciata, p. 30, t. 10, 
f. 39 ... M. rufescens, p. 30, t. 10, f. 30... M. triangularis, p. 31, 
t. 10, f. 40... M. lactea, p. 31, t. 10, f. 41 ... M. ovalina, p. 31, t. 10, 
£23: ..:) Mi alba; p. 31; t. 10¢f. 276. Vi squalida, pelt. ingore 
M. Brasiliana, p. 31, t. 10, f. 60 ... M. Lisor, p. 32, t. 11, f. 54, 55 
so. M. truncata, p. 82, t. 9). 1.3. Australis, p32; t: 10; 1. 36) 
M. elegans, p. 33, t. 11, f. 16 ... M. vitrea, p. 38, t. 10, f. 28 ... 
M. exoleta,.p. 38, t. 11, f. 51... M. elongata, p. 33, t. 10, £2... 
M. Saulia, p. 34, t. 18, f. 24... M. (1?) nucleus, p. 34, t. 12, f. 11 
.. ML. (Mulinia) bicolor, p. 34, t. 10, f. 31... M. ( Mulinia) lateralis, 
p- 34, t. 10, £25... M. (Mulinia) Donaciformis, p. 34, t. 10, f. 29... 
M. (Mulinia) Byronensis, p. 35, t. 10, f. 38. 
Gnathodon cuneatus, p.35, t. 10, f.22. See, likewise, G. rostratus, 
parvus, and trtgonus of Petit (J. Conch. vol. 4). 
Crassatella Kingicola, p. 35, t. 12, f.17 ... C. Donacina, p. 36, 
t. 10, £. 58... C. suleata, p. 86, t. 12, £22 ©... C. rostrata, p. 36, 
t. 9, -f 81... Chsubradtata; sp. 36; 4: '9, 4-12;-and't- 12) ala... 
C. casianea, p. 36, t. 12, £23... C. decipiens, p. 36, t. 11, £9... 
C. pulchra, p. 36, t. 12, £18... C. lapidea, p. 36, t. 10, f.59 ... C.gubar,. 
p- 37, t.12, f. 25... C. Corbuloides, p. 37, t. 12, £15 ... C. triquetra, 
