MODIOLA. 187 



The interior does not appear in those we have examined 

 to be very pearly, but stained behind with liver colour. 



There is a well-marked rib-like callus which strengthens 

 the hinge-margin in front just beneath the beaks, at the 

 summit of which the hinge-margin appears when very 

 highly magnified, to be snbdenticulately corrugated as in 

 the genus Iridina. There are a few minute marginal 

 crenulations also behind the cartilage. 



This interesting species, first published as British by Mr. 

 Jeffreys, in 184-7, is probably not very uncommon, and has 

 been passed over as the young of Modiolus. He had 

 observed it in the Hebrides as long ago as 1843. Since 

 then it has been taken not unfrequently by Mr. M 'Andrew 

 on the west, and by Lieut. Thomas on the north-east 

 coasts of Scotland. It had previously been observed in 

 Sicily, but only in a fossil state. 



M. tulipa, Lamarck. 



Never large ; always rayed with crimson or violet, smooth ; 

 byssal filaments obscure if present ; posterior edges sub-retuse ; 

 beaks not quite terminal. 



Plates XLV. fig. 7, XLVIII. fig. 6, and (Animal) plate Q. fig. 6. 



Lister, Hist. Conch, pi. 359, f. 198 ?— Knorr, Deliees des 

 Yeux, pt. 4, pi. 15, f. 3 (probably). 

 ? Mytilus Modiolus, Chemn. Conch. Cab. vol. viii. pi. 58, f. 758. 

 ? Modiola Americana, Leach, Zoolog. Miscellany, vol. ii. p. 32, pi. 72, f. 1. 



„ tulipa, Lam. Anim. s. Vert. (ed. Desh.) vol. vii. p. 19 (partly). — 



Sowerby, Genera Shells, Modiola, f. 5 (probably). — Philippi, 



Moll. Sicil. vol. i. p. 69, and vol. ii. p. 50. — Sowerby, Conch. 



Manual, f. 160 ?— Reeve, Conch. Systemat.vol. i. pi. 101. f. 5 (prob). 



„ radiata, Brit. Marine Conch, p. 249, f. 104. 



„ Papuana, young, Brown, Illust. Conch. G. B. p. 77, pi. 27, f. 5, 6. 



It is not improbable that formerly this elegant little shell 

 has been passed over in Great Britain as the young of 



