3^20. EIIYCINID:;®. 



cies, is viviparous, and lives as much out of the sea as in it. 

 Other species occur in various parts of the world." — Jeffreys. 



Lepton, Turton, 



Etym. — Lepton^ a minute piece of money (from leptos, thin). 



Syn. — ? Solecardia (eburnea), Conrad, 1849. 



Disti\ — 20 sp. Universal. Laminarian and coralline zones. 

 Fossil, 5 sp. Eocene — ; United States, Europe. L. squamosum, 

 Mont, (cxx, 61). 



Shell suborbicular, compressed, smooth, or shagreened, a little 

 opened at the ends and longest behind ; hinge-teeth O'l or 1*1 in 

 front of an angular cartilage-notch ; lateral teeth 2'2: and l-l. 



Animal with the mantle open in front, extending bej'^ond the 

 shell, and bearing a fringe of filaments, of which one in front is 

 very large; siphon single, gills two on each side, separate ; foot 

 thick, tapering, heeled and grooved, forming a sole or creeping 

 disk. — Alder. 



Pristophora, Carpenter, 1866. 



Distr. — P. oblonga, Carp. San Diego, Cal. 



Shell oval, with two diverging teeth in each valve, the anterior 

 being conspicuouslj^ shorter than the posterior, sulcated near the 

 beaks, ligament situated in a groove between them. 



Kellia, Turton, 1822. 



Utym.— Named after Mr. 'Kelly, of Dublin. 



Syn. — Cycladina (Adansonii), Cantr. 



Distr. — 35 sp. Norway, New Zealand, California. Fossil, 20 

 species. Eocene — ; United States, Europe. K. suborbicularis, 

 Mont, (cxx, 92). 



Shell small, thin, suborbicular, closed ; beaks small; margins 

 smooth ; ligament internal, interrupting the margin (in K. sub- 

 orbicularis), or on the thickened margins (in K. rubra) ; cardinal 

 teeth 1 or 2, laterals 1 — 1 in each valve. 



Animal with the mantle prolonged in front into a respirator}'- 

 canal, either complete (in K. suborbicularis) or opening into the 

 pedal slit {in K. rubra) ; foot strap-shaped, grooved ; gills large, 

 two on each side, united posteriorly, the external pair narrower 

 and prolonged dorsally ; palpi triangular ; posterior siphonal 

 orifice single, exhalent. 



The hinges of these little shells are subject to variations, 

 which are not constantly associated with the modifications of 

 the mantle -openings. They creep about freely, and fix them- 

 selves by a byssns at pleasure. K. rubra is found in crevices of 

 rocks at high-water mark, and often in situations only reached 

 by the spray, except at spring-tides ; other species range a:s 

 deep as 200 fathoms. K. Laperousii (Chironia), Desh., was 

 obtained, burrowing in sandstone, from deep water, at Monterey, 

 California. 



