EXPLANATION OP PLATE XVI. 



Saxuava niLiNEATAConriul (]). 93). 



Puis. 1, 2. Extciior natural size and enlarged interior view of a sLort lii<iad form. 

 3. View 111' an inipc^rfect riglit valve of an elongate form = .S'. riitittxii \.. 



.SAXl<:A^■A MY/KKORMis Conrad (p. 90), 



Puis. 4,5. Exterior ottlie sliell, natnr;il size, and enlargement of the hinge. Type speetmen. 



,SaxU'a\ A I'AUii.i.s (,'onrad (p. 92). 



Pig. ti. View of the type specimen, natural hIzc. 



I'KHiruiMA ALTA Conr.ad (p. K>). 



PitfS. 7. Hxterior view of a Hi)c'eimen, showing the imprint of the internal rib on the right of the 

 heak. 

 ^. Interior of t'<inra(rs type specimen, showing hinge structure. 



Mya j'anoivka Ooldfussi (p. .S9). 



Pics. 9, 10. Kxterior and interior views of the best valve ohtaineil; the hinge broken. 



11. Hinge <d' a fragment of a left valve. 



12. Hinge of a right valve, looking parallel to the jdane of the valve. 



13. Hinge of a right valve; the tooth broken away at «. 



