INDEX 



587 



Popofsky, 247 22 , 286 20 

 Population density, 143 



abyssal, 255 



in cold seas, 275 

 Porcellio, 44, 466 

 P. scaber, 379 

 P. piclus, 47 



Porites, 207, 208, 214, 215, 221 

 Portax pictus, 548 

 Portier and Duval, 55 10 

 Portlandia lucida, 194 

 Portmann, 35S 87 

 Portunus, 188 

 Posidonia, 180 

 Posso, Lake, 86 

 Potamides, 101, 114, 197 

 P. ebeninus, 205 

 Potamobius, osmotic pressure of body 



fluids, 34 

 Potamochoerus, 519 

 Potamogale, 474 

 Potamogeton, 292, 348 

 Potamon, 347 

 Poterion, 216 

 Praecocial birds, on bird islands, 484 



of the steppe, 463 

 Prairie formation, 444 

 Pratt, 27, 31 10 , 55 13 , 147 

 Preble, 376 17 , 420 126 

 Predatory beetles in rain-forests, 426 

 Prehensile tails, 425 

 Pressure, 396 



an environmental factor, 19 



of sea water, 150 

 Priapulus caudatus, 277, 285 

 P. caudatus forma tuber culatospinosa, 111 

 Primitive southern forms, 112 

 Primnoa, 267 



Pringleopsis kerguelensis, 525 

 Prionastraea, 209 

 Pristiophorus, 189 

 Pristis, 189 

 Procavia crawshayi, 78 

 P. valida, 78 



Production aggregations, 239 

 Prosocenlrum micans, 244 

 Prosopis, 112 

 Prosopistoma, 313 

 Prostherapis, 107 

 Protection against desiccation, 47 



Protective devices, in the coral reef com- 

 munity, 220 

 Proteles, 112 

 P. cristatus, 403 

 Proterhinus, 518 

 Proteus, 395, 527, 531, 532 

 P. anguineus, 94 

 Protodrilus, 184 

 Protopterus, 114, 354 

 Protozoans in Lake Baikal, 346 



extended range, 127 



fresh-water, 295 



marine, 227 



saline waters, 371 

 Prschewalski, 319 23 , 464, 468 10 ' «• 70 

 Prunella, 497 



Pruvot, 162 5 , 175 6 , 178, 221 1 

 Psammobia, 185 

 Psenes, 220 

 Psephenus, 313 

 Pseudanophthalmus, 537 

 Pseudocalanus elongatus, 286 

 Psuedocuma, 347 



diversification in the Caspian, 79 

 P. abbreviata, 80 

 P. campylaspoides, 80 

 P. diastyloides, 79 

 Pseudodiaptomus gracilis, 304 

 Pseudograpsus, 37 

 Pseudosinella alba, 537 

 Psilura monacha, 68 

 Ptenopus, 466 

 Pteroclurus, 450 

 Pterocnemia pennata, 388 

 Pterophryne, 246 

 P. histrio, 245 

 Pteropod ooze, 250 

 Pteropus, 427 

 Pterygioteuthis, 259 

 Pudu humilis, 423 

 Puerto Rico, amphibian and reptile 



fauna, 132 

 Puff, 175 12 

 Puffinus, 787 

 P. assimilis baroli, 486 

 Puget Sound, benthos, 195 

 Puncturella noachina, 278 

 Pupa, 70 



Pupa maritima, 417 

 Pupidae, 509 



