EXPLANATION OF PLATK XIX. 



Tkitia ■|■|<lvrTTATOllll•:^^ Wliit.l'. (p. KM). 



Fl(is. 1, 2. Enlargi'd views ol' two iliUereut spei'liui-ns; onr wit limit llu^ vMiix. tlie other haviiifj it. 



3. Surface still further enlarged. 



Titni A ■ntiXATrAioiuns var. ki.onii.vta ( |p. lO'i). 



Figs. 4,r>. Two views of a S|ie('iiiii'ii. The figures are too broad in proportion to theii length. 



G. \'iew of another speeimeu, showing more nearlv the true proportions, enlarged. 



Tritia iudext.^ta Emu.ons sp. (p. lOfi). 



Fl(i. 7. Enlarged view of ,i large individual of the sjiecies. 



1)1, IVA ('aI{i>mne.\si,s t'onrad (p. 1(19). 



Fill. X. Copy of Mr. Conrad's figure from the Aiueriean .loiirnal of Science and Arts, vol. 41, 



1st ser., PI. II, lig 1. 



EraTi) Emmun'SI Whitf. (ji. 108). 



Figs. !I. 10. 11. Three views of the only perfect specimen found, enlarged. 



Amyci.a coMMi'Nis Conrad (p. 110). 



Fius. VJ, i:f. Two views of one of the larger specimeus, enlarged. 



14, 15. Similar views of another individual which shows color Hues on part of the shell. 



