MARINE MOLLUSCA OF MADEIRA. 265 



bordered by a remote longish narrow lamina which rises into a 

 small rounded prominence. Inside glossy, with a suggestion of 

 faint radiating lines in the inner substance of the shell. — L. 0'13. 

 H. 009. 



Eare ; but found by Mr. Lowe and Mr. Johnson as well as 

 myself. I dredged it both at Funchal and at Punta de Sao 

 Lourenco. This species is much more triangular than Jf. biden- 

 tata, Mont., and much more oval than M. striata, Mont. 



Fam. Ctpeinidj. 

 Gren. Coralliophaga, de Blainv. 



34. CORALLIOPHAGA JOHNSONI, n. sp. 



Shell very irregularly rhomboidally oval, the straightish hinge- 

 margin which runs out in front to a small bluntly rounded 

 corner being vaguely parallel to the rounded lower margin, while 

 the oblique straight but slightly incurved front line is in a way 

 parallel to the easy sweep of the convex, almost semicircular 

 curve of the posterior margin : the valves are tumid above and 

 in front, but are a little compressed behind and below ; they are 

 in substance thin, subpellucid and fragile, with fine sharpish 

 but unequal concentric lines of growth. Colour dirty yellowish 

 white, with a chestnut tinge towards the beaks. Epidermis very 

 thin, worn oft* except towards the hind margin, where it shows a 

 tendency to slight irregular puckering. Beaks small, rounded, 

 polished, pointing forwards, and bent in on the hinge-line so as 

 to meet one another ; they lie a little in front of the middle of 

 the dorsal margin. Margins : they fit quite closely, and, where 

 the lips are not inverted, meet one another in the face abruptly, 

 except below where the shell is slightly flattened out. Ligament 

 ruddy brown, thin but strong, prominent, short, ceasing abruptly 

 at the beaks. Hinge-line straight, narrow. Teeth : there are 

 three small rounded laminae in each valve, forming a little shelf 

 on the inner side of the hinge-margin ; they are nearly parallel 

 with the hinge-margin ; the front one, which is a little hummocky, 

 is the shortest ; the second, which is directly under and behind 

 the beak of the shell, is longer and more compressed; while the 

 posterior one is somewhat vaguely spread out and cut up ; in the 

 left valve it is a little more developed than in the right, other- 

 wise in the two valves the teeth are very much alike. Inside not 

 nacreous, but doubtfully opalescent, only vaguely fretted, quite 



LINN. JOURN. — ZOOLOGY, VOL. XXVI. 20 



