AETEMIS.— Plate III. 



grooved throughout, intermediate ridges regular, 

 appressed, rather sharp at the sides, area of the 

 ligament simple, lunule oblong-cordate, impressed; 

 shining wliite. 



Hub. North Australia ; Jukes. 



Allied to the typical species of the genus ^i. concentrica, 



from which it differs mainly in being more tnily orbicular. 



Species 17. (Mus. Cuming.) 



Aetemis Japonica. Art. testa suborbiculari, comjiressd, 

 aliquauto laiiore gumn altd, postice stiperne angulosd, 

 eoncentrice subtiUter eleoato-striatd, atriis ad latera 

 paucioribus, sublamellatis, area ligamerdi late excavald, 

 margine subproductd et obscure spinosd, lunula oblongo- 

 cordatd, impressd ; sordid} carneo-cinerascente. 



The Japan Artemis. Shell nearly orbicular, a little 

 broader than high, posteriorly angular along the 

 upper part, concentrically finely elevately striated, 

 strise fewer and slightly lamellated at the sides, area 

 of the ligament broadly excavated, somewhat produced 

 and obscm'ely spinose along the edge, lunule oblong- 

 cordate, impressed ; didl flesh-tinged ash-colour. 



Halj. Japan; Dr. Sicbold. 



A very characteristic species, of quite a different type 

 from those of North Australia, being closely sculptured 

 with sharp, raised striae, which diminish materially in 

 number at the sides and incline to form lamellae. 



Species IS. (Mus. Cuming.) 



Artemis plana. Art. testa orbiculari, .mperni subacumi- 

 natd, pecttliariter plano-compressd, comentrice subtilis- 

 sime et creberrime striatd, striis medio plies minus 

 obsoletis, ared ligamenti simplici, lunula oblongo-cor- 

 datd, unibonibus parvis ; albd, epidermide corned tenu- 

 issimd marginem versus indutd. 



The flat Arte.mis. Shell orbicidar, somewhat acu- 

 minated towards the upper part, peculiarly flatly 

 compressed, concentrically very finely and closely 

 striated, strife more or less obsolete in the middle, 

 area of the ligament simple, lunule oblong-cordate, 

 umboes small ; white, covered towards the margin 

 with a thin homy epidermis. 



HaJj. China. 



Remarkable for its thin, compressly flattened growth. 



whilst the concentric sculpture is so fine that it might 



escape observation. 



