EXPLANATION OF PLATE XXIX. 



FiGUKE 203. — Astarte undata, (p. 684 ;) somewliat reduced. 

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

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

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

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

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

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

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

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

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

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

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

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

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



(Figures 203, 207, 214 were drawn by A. E. Yerrill ; 215 by E. S. Morse ; the rest from Binney's Gould, 

 and mostly drawn by E. S. Morse.) 



