26 
THE NAUTILUS. 
Subfamily Mactrinje. 
Genus MACTRA (L.) Lam., 1799. 
(-f Crassatella [cygnea] Lam., 1799) ; Type 31. stultorum L. 
Mactra Richmondi Dali. Greytown, Nicaragua. 
Subgenus Mactrella Gray, 1853. 
(+Papyrina Morch, 1853) ; Type : 
Mactra (Mactrella) alata Spengler, 1S02. Porto Rico to Brazil. 
=31. carinata Lam., 1818 ; -f -31. striatula Auct. non L. 
Subgenus Mactrotoma Dali. 
(=Standella Cpr. ex parte, non Gray ; Sjnssida Morcb non Gray). 
Anterior left lateral tooth bidentate, right ventral tooth triden- 
tate. Type: 
Mactra (Mactrotoma) fragilis Gmelin, 1792. Hatteras to Rio Janeiro. 
=il/. dealbata Pult. 1803; -\-M. brasiliana Lam., 1818; + 31. ob- 
longa Say, 1822; -\-M. ovalina (Lam.?) Auct.; +31. oblongata 
Ravenel, 1834; +31. bilineata (C. B. Ads.) Reeve, 1854; +31. sili- 
cula Reeve non Desh. (?) 1854; +31. ambigua Weink. (?); +31. 
anserina Guppy, 1875. Not Spisula fragilis Gray, 1838. 
Genus SPISULA Gray, 1838. 
(=S])issida Phil., 1847, not Morch, 1853 ; +Spizula Conr., 1868 ; 
+Spisulina Fischer, 1887). Type 3Iactra solida L., Gray, 1847. 
Subgenus Hemimactra Swainson, 1840. 
Spisula (Hemimactra) solidissima Dilhvyn., 1817. Labrador to Virginia. 
=31. gigantea Lam., 1818; +31. proeera Sol., mss.; +31. Sayi 
Gray, 1838. 
S. (Hemimactra) solidissima var. similis Say, 1822. Rhode Id. to St. Thomas, 
W. Indies. 
=31. Raveneli Conr., 1831 ; not 31 similis Gray, 1828. 
Section 3Iadromeris Conrad, 1868. 
Spisula (Hemimactra) polynyma Stimpson, 1S60. Hudson Bay to Cape Ann, Mass 
=31. ovalis Gld., 1840, not J. Sowerby, 1817 ; +31. ponderosa 
Phil., 1844, not Eichw. nor Conr., 1830 ; +31. grandis Desh., 1830, 
not Gmel., 1788; +31. similis Gray, 1828, not Say, 1822; +31. 
Grayana Schrenck, 1867. 
