ANODON CICONIA. 



Anodon ciconia, Gould; Proc. B. S. N. H., Nov. 1851. IV. 92 



T. solidula. transversa, oblongo-ovata, ventricosa, epidermide lutescenti-cornea 

 induta : apicibus ad trientem anticum long, sitis, eminentibus, acutis ; latere 

 antico angusto, rotundato ; latere postico dilatato, ad apicem acuto, margine 

 dorsali baud angulato ; margine ventral! rectiusculo, antice hiante, declivitate 

 postico tumido, baud angulato ; margarita ex ochracea incarnata demnm argen- 

 tea ; cavositas apicalis ampla. 



Shell rather solid, transversely oblong ovate, ventricose ; epider- 

 mis yellowish horn color : beaks at the anterior third, prominent, 

 acute; anterior half narrowed, the dorsal margin direct or a little 

 concave, extremity rounded, a little above the middle ; posterior 

 half widening ; dorsal edge at first a little arched, then obliquely 

 truncate, but without forming an angle ; tip acute ; ventral margin 

 nearly straight, gaping anteriorly ; posterior umbonal slope tumid, 

 and not angulated. Nacre ochreous, tinted flesh color on the disk, 

 becoming silvery at margin ; cavity of the beaks capacious. 



Length four inches ; height two and three eighths inches ; breadth 

 one and o le fourth inches. 



From the Collection of Lieut. Green, and marked " Mexico (?)." 

 It is evidently an equatorial type, and closely resembles A. anse- 

 rma, from Brazil. It is thicker in substance, more tumid on the 

 posterior half, the epidermis and nacre are quite differently colored. 

 The posterior dorsal and ventral margins have a corresponding 

 slope, a little arched, and come together at the middle of the alti- 

 tude. It is more like A. implicata than any other North American 

 species. 



MYTILUS GLOMERATUS (PI. XVI. Fig. 8.) 

 Mytilus glomeratus, Gould; Proc B. S. N. H., Nor. 1851. IV. 92. 



T. parva, solidula, arcuatim oblongo-ovata, nitida ex indica nigrescens, pos- 

 ticeobtusa; apicibus remotis, excurvatis; valvis ventricosis oblique sub-angu- 

 latis, margine ligamentali recto, demum subitb arcuato ; margine ventrali recto 

 vel excavate; cardo altera valvii dentibus duobus, altera tribus; intus argen- 

 tata, ad limbum nigra incrassata et radiatim striata ; cicatricibus profundis. 



Shell small, oblong ovate, arcuate, rather solid, shining, stria? of 

 growth conspicuous, deep indigo blue passing into jet black, at the 



