28 THE NAUTILUS. 
Labiosa (Raeta) canaliculata Say, 1822. New Jersey to southern Brazil. 
—=Mactra campechensis Gray, 1828. 
Doubtful or spurious East American species. 
Mactra nucleus Conr., 1831, from “New Jersey” is exotic, and 
stated by Tryon in the Am. Marine Conchology to be a native 
of Manila. 
Mactrella (Harvella) elegans Sowerby, has been reported from 
“Florida” where it is unknown, and ‘“ Jamaica”’ probably by 
a misidentification. There is no specific difference between 
Panama and alleged Antillean specimens and the name cannot 
be admitted to the East American list without further evidence. 
Spisula subtruncata Da Costa. What appears to be a somewhat de- 
formed subfossil valve of this species was sent from Lawlor’s 
Lake, New Brunswick, to Dr. Stimpson by Matthews, many 
years ago. It is in the National Collection but no other spec- 
imen seems to have been collected on this side of the Atlantic 
and it is probably a ballast shell. 
Spisula solidissima var. Acadica Matthews; Can. Nat. viii, no. 2, p. 
111, 1877, from the higher clays beds at St. Johns, N. B. See 
also Ann. Soc. Mal. de Belgique ix, 1874. This may be 
founded on the specimen of S. subtruncata above mentioned, 
though Mr. Matthews’ paper is not sufficiently explicit to deter- 
mine. It is probably an exotic as he suggests. 
Spisula “ subimbricata Mont.” Cockerell, in list of Jamaica shells, 
Nautilus, vii, p. 115, 1894. Montagu described no Mactra of 
this name. What the shell intended may be, is of course im- 
possible to say, but possibly the following : 
Mactra Richmondi n.s. Shell thin, small, white, inequilateral, with 
the posterior end shorter and its dorsal aspect obtusely keeled ; 
surface nearly smooth, except the dorsal areas, which hayveshort 
deep concentric grooves; beaks moderate, adjacent; lateral 
teeth rather short and small, smooth; pallial sinus small, 
rounded, extending forward to the vertical of the beaks ; poste- 
rior end obtusely pointed. Longitude 21; alt. 14; semi- 
diameter 4.5 mm. 
One valve on the beach at Greytown, Nicaragua; Chas. Rich- 
mond. It isthe only American species belonging to typical 
Mactra with grooved dorsal areas. 
Mactra Cumingiana “ Bush,” Zool. Rec., 1885, from Cape Hatteras, 
is a lapsus of the Recorder for Mactra Cumingiana. 
