SOLENID. 133 
seen in species of Tagelus. Externally the type species resem- 
bles the recent Pharella Javanica. 
Siriqua, Muhlfeldt, 1811. 
Syn.— Leguminaria, Schum., 1817. Machera, Gld., 1841. 
Aulus, Oken., 1815. 
Distr.—20 sp. India, China, Ochotsk, Oregon, Sitka, Behr- 
ing’s Sea, Newfoundland, Atlantic United States. M. costata, 
Say, is often obtained from the maw of cod-fish. Fossil, 4 sp. 
Upper Greensand—,; Britain, France. S. radiata, Linn. (evi, 13). 
Shell smooth, oblong; epidermis polished ; an umbonal rib 
extending across the.interior of the valve; pallial sinus short. 
The animal is similar to Solecurtus. 
Protuyris, Meek, 1869. 
Distr.—2 sp. Carb.; U.S. P. Meeki, Winchell (ev, 90). 
Shell equivalve, very inequilateral, longitudinally oblong ; 
valves compressed or moderately convex ; nearly closed or a 
little gaping behind, and more or less widely gaping in front, 
where the hiatus is increased in size by a nearly rectangular 
notch in the margin, mainly below the middle; beaks depressed 
and very near the anterior end, with a small ridge usually 
extending from the anterior side of each to the corner of the 
anterior marginal notch; dorsal margin.without escutcheon or 
lunule, being erect and sharp behind the beak; surface merely 
marked with striz of growth. Hinge and interior unknown. 
Sotecurtus, Blainv., 1824. 
Syn.—Solenocurtus, Sowb., 1839. Tagelus, Gray, 1847.  Sili- 
quaria, Schum., 1817. 
Distr.—11 sp. E. and W. Coasts of N. and S. America, Sene- 
gal, Mediterranean. Fossil, 30 sp. Neocomian—; United 
States, Europe. S. Dombez, Lam. | ev, 87). 
Shell elongated, rather ventricose, with subcentral beaks ; mar- 
gins subparallel; ends truncated, gaping; ligament prominent ; 
hinge-teeth two in each valve; pallial sinus very deep, rounded ; 
posterior adductor rounded. 
Animal very large and thick, not entirely retractile within the 
shell; mantle closed below; pedal orifice and foot large; palpi 
triangular, narrow, lamellated inside; gills long and narrow, 
outer much the shortest; siphons separate at the ends, united 
and forming a thick mass at their bases; anal orifices plain, 
branchial fringed. 
The Solecurti bury deeply in sand or mud, usually beyond 
low-water, and are difficult to obtain alive. P. Caribeus occurs 
in countless myriads in the bars of American rivers, and on the 
coast of New Jersey in sand exposed at low-water ; by removing 
three or four inches of sand its burrows may be discovered ; | 
