460 MANUAL OF THE MOLLTTSCA. 



MoNTACUTA, Turton. 



"Dedicated to Colonel George Montagu, the most distinguished 

 of the earlier English malacologists. 



Type, M. substriata. PL XIX., Fig. 13. 



Shell minute, thin, oblong, anterior side longest ; hinge-line 

 notched ; ligament internal, between 2 laminar, diverging 

 teeth (with a minute ossicle. Loven.) 



Animal "With the mantle open in front ; margins simple ; 

 siphonal orifice single ; foot large and broad, grooved. 



The Montacutce moor themselves by a byssus, or walk freely ; 

 M. siibstriata has only been found attached to the spines of the 

 purple heart-urchin {Spafangus purpureus) in 5 — 90 fathoms. 

 M. hidentata burrows in the valves of dead oyster- shells. 



Distribution, 3 species. United States, Norway, Britain, 

 ^gean. 



Fossil, 2 species. Pliocene — . Britain. 



Lepton, Turton. 



Etymology, lepton, a minute piece of money (from leptos, thin). 

 Synonym ? Solecardia (eburnea) , Conrad, Lower California. 

 Type, L. squamosum. PI. XIX., Fig. 14. Fig. 256. 

 Shell sub-orbicular, compressed, smooth, or shagreened, a 

 little opened at the ends and longest behind; hinge -teeth 0.1 

 • or 1.1 in front of an angular 



cartilage notch; lateral teeth 

 2.2 and 1.1. 



Animal with the mantle (m) 

 open in front, extending beyond 

 the shell, and bearing a fringe 

 of filaments, of which one in 



Fig. 256. Lepton. ^^"^^ ^^^ '^ 7^^^ ^^^^® ' ^'P^^^^ 



(s) single, gills two on each side, 

 separate ; foot (/) thick, tapering, heeled and grooved, form- 

 ing a sole or creeping disk. (Alder.) 



Sub-genus. Scintilla (Cumingi), Desh. 1856. Small shells 

 resembling Lepton ; minutely punctate ; ligament internal, 

 oblique; hinge-teeth 1. 2; posterior laterals 1. 2. Distribu- 

 tion, 37 species (?), Philippines, North Australia, Panama. 



Distribution, 50 species. United States, Britain, Spain. 

 Laminarian and Coralline Zones. 



Fossil, 5 species. Pliocene — . United States, Britain. 



