EXPLANATION OF PLATE XXIX. 



FiGur.E 203. — Astarte nudata, (p. Gti4 ;) somewhat reduced. 

 204. — Astarte castanea, (p. 685;) natural size. 

 205. — Astarte quadraus, (p. 685 ;) natural size. 

 206. — Gouldia mactracea, (p. 685 ;) natural size. 

 207. — The same, inside of one valve, enlarged. 

 208. — Laevicardiuni Mortoni, (p. 683;) natural size, with animal. 

 209. — Cardium pinnulatum, (p. 683;) natural size. 

 210. — Soleuomya velum, (p. 688;) natural size. 

 211. — Cyclas dentata, (p. 686 ;) natural size. 

 •212. — Luciua filosa, (p. 686;) natural size. 

 213.— Cryptodou Gouldii, (p. 686;) enlarged two diameters. 

 214. — Cryptodou obesus, (p. 687;) enlarged three diameters. 

 215. — Cyclocardia Novauglise, (p. 684;) natural size. 

 216. — Cyclocardia borealis, (p. 683;) natural size. 



(Figures 20;?, 207, 214 were drawn by A. E. Terrill ; 215 by E. S. Morse ; tbe rest from Binney's Gould, 

 and mostly drawn by E. S. Morse.) 



