Orvanne, 109 _Œscus_, 31 Oskol, 31 Otter, 34 Ource, 78 Ourcq, 41 Ourt, 138 Ousche, 32 Oust, 158 Owenbeg, 164 Ovoca, 153 Oxus, 31 Paar, 65 Pader, 132 _Padus_, 132 Palme, 67 Pant, 178 _Pantanus_, 132 Parde, 133 Parret, 83 _Parthenius_, 133 _Pathissus_, 132 _Paulo_, 178 Pebrach, 84 Pedder, 83 Peen, 81 Peffer, 83 Pelym, 67 _Peneus_, 82 Penjina, 82 Penk, 82--Note. Pennar, 82 Penza, 82 _Permessus_, 154 Pernau, 65 Persante, 101 Petteril, 83 Pever, 83 Pfreimt, 154 Piana, 82 Piave, 65 Piddle, 82 Pina, 82 Pinau, 82 Pindar, 83 _Pindus_, 82 Pinega, 82 Pinka, 82 Pitrenick, 83 Plaine, 65 Plau, 65 Plan-see (Lake), 66 Pleiske, 67 Pleisse, 66 _Pleistus_, 66 Pliusa, 66 Ploen (Lake), 66 Plone, 66 Plonna, 66 Plym, 67 Po, 131 Polota, 85 _Porata_, 115 Portva, 115 _Practius_, 167 Pravadi, 115 Pregel, 115 Primma, 154 Prims, 154 Pripet, 115 Pronia, 115 Prosna, 101 Prüm, 154 Pruth, 115 Purally, 115 _Pydaras_, 83 _Pyramus_, 154 Queiss, 158 Quenny, 145 Quipar, 177 Raab, 120 _Rasa_, 96 Rasay, 96 Ravee, 102 Raven, 102 Rea, 43 Rednitz, 95 Reen, 43 Rega, 43 Regen, 43 Regge, 43 Reno, 43 Reuss, 96 Rezat, 96 _Rha_, 43 _Rhesus_, 96 Rhine, 43 Rhion, 43 _Rhodanus_, 95 _Rhodius_, 95 Rhone, 95 Riaza, 96 Riga, 43 Riss, 96 Robe, 102 Rodach, 95 Rodau, 95 Rodden, 95 Roer, 168 Rohrbach, 168 Ross, 96 Rosslau, 96 Rötel, 96 Roth, 95 Rotha, 95 Rothaine, 95 Rother, 96 Rott, 95 Rottach, 95 Roubion, 102 Ruhr, 168 Rye, 43 Saale, 76 Saar, 55 _Sabis_, 59 Sabor, 59 _Sabrina_, 59 Saima (Lake), 119 Sal, 77 Salm, 166 _Salo_, 77 Salza, 151 Samara, 119 Sambre, 59, 119 San, 166 Saone, 119 Saraswati, 56 Saratovka, 56 _Sarayu_, 55 Sare, 55 Sark, 55 Sarnius, 56 Sarno, 56 Sarsonne, 56 Sarthe, 56 Sau, 59 _Sauconna_, 119 Save, 59 Savena, 59 Savezo, 59 Savio, 59 Savranka, 59 Sazawa, 98 _Scaldis_, 159 Scarr, 162 Scheer, 162 Scheldt, 159 Schie, 161 Schiltach, 159 Schmida, 53 Schnei, 52 Schondra, 99 Schozach, 99 Schunter, 99 Schupf, 101 Schussen, 99 Schutter, 99 Schwabach, 101 Schwale, 165 Schwalm, 166 Schwarza, 150 Schyrne, 162 _Scius_, 161 _Scopas_, 101 Seaton, 141 Seena, 166 Segre, 119 Segura, 119 Seille, 76 Seine, 119 Selle, 76 Selse, 151 Selune, 77 Sem, 119 Semoy, 119 Sempt, 119 Sena, 166 Senne, 166 _Senus_, 166 Seran, 56 Serchio, 55 Sered, 56 Sereth, 56 Serio, 55 Serre, 55 Serus, 55 _Sessites_, 98 Sestra, 99 Seugne, 119 Seva, 59 Sevan, 59 Severn, 59 _Severus_, 59 Sevre, 59 Sevron, 59 Shannon, 166 Sheaf, 101 Shere, 162 Shiel, 169 Shin, 166 Shira, 162 _Sicoris_, 119 Sid, 141 Sieg, 119 Sieve, 59 Sihl, 169 Silaro, 169 Sile, 169 Simmen, 119 Simmer, 119 _Simois_, 119, 169