93 



Pinna senticosa. T. cuneata, sub-inflata, postice oblique 

 rotundata, purpureo-nigricans ; margine dorsali sub-a?cendente ; 

 margine ventrali prope apicem pendulo : area triangularis superior 

 costulis ad 7 radiantibus squamigeris (squamis semi-tubulosis) 

 instructa ; area inferior striis incrementalibus solum notata. 

 Long. 4£ ; alt. 2£ ; lat. 1 poll. Hab. New Zealand. 



Its general appearance is tbat of P. seminuda; but it is 

 smaller, much darker, the ventral margin is less arcuated, and 

 the scales much less numerous and regular. 



Mytilus (Modiola) flabellatus. T. transversa, ploneata, 

 trapezoidea, trifariam cuneata ; umbonibus minime terminalibus, 

 acutis, attigentibus ; declivitate nmbonali ventricoso, angulato ; 

 marginibus rectilinearibus ; latere postico oblique truncato, haud 

 angulato ; epidermide antice nitido, exusto, postice flavo-viridi, 

 flosculis rigido : intus exalbida. Long. 4 ; alt. If; lat. 1|- poll. 

 Hab. Puget Sound, Oregon. 



A very well marked species, more than usually cuneate, and 

 with the beaks quite remote from the summit. 



Mytilus (Modiola) areolatus. Testa transversa, ovafo-elon- 

 gata, incurvata, tumida ; umbonibus approximatis, angulatis, fere 

 lerminalibus; margine dorsali arcuato ; margine ventrali i'orni- 

 cato, valde hiante ; epidermide nitido, castaneo, portione antico- 

 ventrali sulco limitato : intus alba, limbo dorsali purpurascente. 

 Long. 2 ; alt. l£ ; lat. 1 poll. Hab. New Zealand. 



Somewhat like M. vulgaris ; the beaks are nearly terminal, 

 the byssal opening broader and nearer the beaks, the ventral 

 margin arching inwards instead of outwards at this point ; the 

 epidermis is darker and more shining, and the nacre is different. 



Mytilus (Modiola) hepaticjs. T. parva, elongata, ovato- 

 triangularis, antice anguslata, ventricosa ; margine dorsali angu- 

 lato ; umbonibus acutis, angulatis; epidermide tenui, livido- 

 corneo, versus fastigium umbonalem flavescente ; intus puni- 

 cea, luteo-marginata. Long. l£ ; alt. f ; lat. f- poll. Hab. Fee- 

 jee Islands. 



A small, elongated species, with its dorsal edge obtusely angu- 

 lar, but best distinguished by its peculiar lurid exterior coloring, 

 and its reddish molybdaena-colored interior. 



