460 



MANUAL OP THE MOLLUSCA. 



MoNTAcxJTA, Tm^ton. 



Dedicated to Colonel George Montagu, the most distlnguislied 

 of the earlier English malacologists. 



Type, M. substriata. PI. 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. siihstriata has only been found attached to the spines of the 

 purple heart-urchin [Spatangus 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. 



<r £y 



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] 

 ©ijen in front, extending beyond 

 the shell, and bearing a fringe 

 of filaments, of which one in 

 front [t) is very large ; siphon 

 (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 (Cum.ingi), 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. 



Fig. 256. Lepton. 



