624 
Old Red sandstones, 110 
Olenellus, 128 
Oneida county, 86, 89 
Onondaga county, 8&9 
Ontario, 87, 92 
Ontogeny, 113-23 
Onychopterus, 133, 150, 159, 212 
kokomoensis, 91 
See also Eurypterus 
Orange county, 6, 87, 105 
Orbiculoidea, 99, I1I 
Oriskany creek, 421 
Orthis elegantula, 100 
Orthoceras, 99 
Orthothetes interstriata, 180 
Osborn, A. O., mentioned, 387 
Ostracophora, 84 
Otisville, 6, 49, 83, 84, 87, 104, 113, 124, 
132, 168, 169, 417 
Otisville basin, 8 
Otsego county, 89 
Owen, R., cited, 33, 72, 433 
Packard, A. S., cited, 40, 120, 136, 433, 
434, 435 
Paedeumias, 128 
Page, D., cited, 278, 432 
Palaeophonoidae, 393 
Palaeophonus, I4I, 142, 143, 147, 387, 
394, 396, 398, 399, 400 
hunteri, 142, 143, 397 
figure, 395 
loudonensis, 397 
nuncius, 143, 147, 391, 394, 397, 400 
figures, 142, 395, 399 
osborni, 387 
Paradoxides, 122 
Parker, G. H., cited, 41 _ 
Patten, W., cited, 35, 54, 82, 85, 86, 140, 
436, 437, 438, 439 | 
Paulmier, cited, 75 
Peach, B. N., cited, 143, 314, 397, 434, 439 
NEW YORK STATE MUSEUM 
Pedipalpi, 141, 142 
Penhallow, D. P., cited, 113, 436 
Pennsylvania, 87, 88, 89, 90, 94, 95, III 
Peter Redpath Museum, acknowledg- 
ments to, & 
Phacops rana, 39 
Phrynus, 66 
Phyllocardia (Echinocaris), 311 
Phylogeny of eurypterids, 124-35 
Pitt, W. H., cited, 15, 91, 228, 349, 359, 
362, 372, 434 
Pittsford, 6, 105; section in old Erie 
canal, 102 
Pittsford pool, 9 
Pittsford shale, 20, 87, 91, 102, 106, IIo, 
161, 421 
Pittsford-Shawangunk, 93 
Plates, explanations of, 441-616 
Platyonichus ocellatus, 51, 71, 75 
oculosus, 72 
Plectambonites sericeus, 325 
Pocock, R. T:, cited, 57, 142, 143, 388, 
390, 394, 397, 398, 399, 438 
Podolia, 95, 97 
Poecilopoda, 147 
-Pohlman, Julius, cited, 16, 91, 108, 201, 
202, 227, 349, 359, 360, 363, 379; 434, 435 
Pores of doublures, 29 
Portage beds, 18, 19, 89, 94 
Portugal, 96 
Portunidae, 75 
Portunus, 75 
Postabdomen, 68-71 
Postoral appendages, 48 
Potonié, cited, III 
Potosi limestone, 90 
Potsdam rocks, 85 
Proscorpionini, 388, 393 
Proscorpius, 387, 394, 396, 398, 399 
osborni, 143, 387-400 
figures, 389 
Prothelyphonus bohemicus, 142 
