Proceedings of the American Academy of Arts and Sciences, Volume 20

Abdomen abdominal appendages Acad acetic acetic acid acid acute Antennæ anthracene appears areola Astacus Barrande base Bentham blastodisc blastomeres border Boston bracts branches broad California calyx Cambarus Cambridge carapace cells Cephalothorax cervical groove chela ciliate cleavage cleavage-plane collected corolla difference of potential Dikelocephalus dorsal Emmons entoderm Eritrichium faune feet flowers foliis fossils fruit genera genus glabrous Graptolites Gray gynobasi Hagen inches long lateral leaflets leaves length less limestone lines long lobes longis Magn male margin maxillipeds median Mountains nearly nuclei Nuculæ nutlets oblong observations Olenus ovum pair of legs papillæ Paradoxides pedicels periblast petioles plate Point Lévis posterior Potsdam precipitate Primordial fauna Proc pubescent punctate ring River rostrum sæpius sandstone schists second fauna segment sepals short side Silurian slates slender somites species specimens spermogonia spines stars superficial tension surface Taconic system telson third tion Trilobites tube upper ventral