﻿M Y A, 



Plate III. 



Species 9. {Flz. o, b.) 



Mya Misdoroessis. M>/a tes/d coiajmsail, alba, lata, 

 lavigatd, ovatd ; latere antiro subinflato, rotundato, 

 umbonibus parvis, submedianis ; latere poslico an- 

 gustidsculo, ]trope marginem dorsalem angulato, 

 post angulum compresso, ad terminumlate truncato, 

 margiiie dorsali brevi, dipresso. 



The Mikdouo Mya. Shell conipresscil, wliitc, broad, 

 smooth, ovate ; anterior .side rather iiUlated, 

 rouuded, uinboes small, nearly central ; posterior 

 side rather narrow, angidar near the dorsil 

 margin, compressed behind the angle, broadly 

 truncated at the end, dorsal margin short, 

 depressed. 



Adams a.nd Keeve ? MS. Mus. Cum, in Urit. 



Hab. Isl. Jlindoro. 



A small shell of the Cnijttumt/a group, dilTering from 



Mya Californica chiefly in the broad posterior truncation. 



jMsllco acuti- aixiiatim amjulnto, angustato, per- 



pendicularitcr truncato ; margiiie dorsali dtprcs.<u, 



rcctiksctilo, complanato. 

 The shortened Mya. Shell ovate, vvliite, smooth, 



anteriorly rounded ; ventral margin convex ; 



posterior side with an acute curved angle, narrow, 



perpendicularly truncated ; dorsal margin de- 



jiressed, rather straight, flattened. 

 A. Adams ? MS. (Cryptomya), Cum. Coll. in Brit. 



Mus. 

 Ilab. Isl. Luzon, I'liilippines. 



Species 10. (Mus. Brit.) 



Mya divaricata. ^fga testa brevi, postice latl-tsime hianti, 

 sxibquadratd, alba, tenuissivic striata ; latere antico 

 semirotundo; umbonibus cleratis.stibaniviinatis; latere 

 postico acute angulato, perpend iculariler truncato, 

 ante angulum undulatim nigato, dicaricatim striata. 



The diveugest Mya. Shell short, with a wide posterior 

 hiatus, rather square, white, very finely striated; 

 anterior side half-round ; uraboes elevated, rather 

 acuminated ; posterior side acutely angular, per- 

 pendicularly truncjited, with wavy wrinkles and 

 divergent striie in front of the angle. 



A. Adams {Crgptnmya). MS. Cum. Coll. in Brit. Mus. 



Jfab. Ceylon. 



Species 11. (Mus. Brit.) 

 Mya DECfRTATA. jl/ya testa ovatd, albA, hevigatd, 

 antic'e subrolundd ; margine ventrali convexd ; latere 



Species 12. (Fig. a, b, Mus. Sowerby). 



My.^ actta. jtfya iestd ovatd, tcmiiusculd, pallide 

 fulvd, concentric!: leviter rugatd, utrinque late 

 /iianti ; latere antico ventricoso, lata ; latere postico 

 cunealo, compresso subrostrato, subacuminato ; im- 

 pressione pallii acuta simiato. 



The acute Mya. Shell ovate, rather thin, pale fulvous, 

 concentrically lightly wrinkled, widely gaping at 

 each end ; anterior side ventrioose, broad ; 

 posterior side cuneate, compressed, rather ros- 

 trated, rather acuminated ; impression of the 

 mantle roundly sinuated. 



Say. Wood's General Conchology. 



Mya Japonica, Say (var.) MS. Mus. Sowerby. 



IJab. North America ; Chupoo, Japan. 



The two specimens figured, the smaller Japanese, the 

 larger Nortli American, resemble each other and differ 

 in the same degree from our common Mya arenaria. 

 They are much more pointed at the end, and have a 

 more rounded sinus in the pallial impression. These 

 differences, however, may be rather varietal than 

 specific. 



May, 



