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462 REV. A. H. COOKE oK [May 17, 



Amphidromus quadrasi. Hid. Peculiar. 



Lamprocystisgoniogyra, Mollf. Also occurs in Philippines generally. 



myops, Semp. & Dhrn. „ Philippines generally. 



succinea, Pfr. „ Philippines generally. 



TrocTionanina labuanensis, Pfr. „ Borneo. 



Hadra ^ monochroa. Shy. Also occurs in Palawan and Busuanga. 



Cochhstyla^ satyrus, Brad. „ Palawan and Busuanga. 



Cyclophorus triliratus, Pfr, „ Borneo. 



Opisthoporus quadrasi, Cr. Peculiar. 



Leptopoma insigne, Sby. Also occurs in Mindoro. 



maculatum, Lea. ,, Luzon. 



— — vitreum, Less. Also occurs in Java, Philippines, Moluccas. 

 Quadrasia hidalgoi, Cr. Peculiar. 



Thus we find, even at the extreme Borneau end of this ridge, 

 Philippine influence of considerable importance. The Bornean 

 Amphidromi are counterbalanced by the Hadra, which belongs to 

 the remarkable group of which the metropolis is Palawan, and by 

 the single Cochlostyla. Opisthoporus, again, is Indo-Malay, while 

 in the genus Leptopoma the preponderance, in species at any rate, 

 is towards the Philippines. Quadrasia is a remarkable freshwater 

 form, apparently allied to Planaxis, and quite peculiar to Balabac. 



The Mollusca known from Palawan are as follows : — 



Hemiplecta schumackeriana, Pfr. Also occurs in Borneo. 

 Hemitrichia (?) plateni, Dohrn. Peculiar. 

 Euplecta cebuensis, Mollf. Also occurs in Philippines. 



Lamprocystisgoniogyra, Mollf ./ ir i- :■ „ Philippines. 



succinea, Pfr. „ Philippines. 



Trochonanina conicoides. Mete. „ Borneo, Bongao. 



Trochomorpha loocensis, Hid. „ Philippines. 



metcalfei, Pfr. „ Philippines, Borneo. 



splendens, Semp. „ Philippines. 



Amphidromus entobaptus, Dohrn. Peculiar, with Balabac. 

 Hadra trailli, Pfr. Peculiar. 



^monochroa, Sby. Peculiar to Palawan, Balabac, and 



Busuanga. 

 Eulotella (?) inquieta, Dohrn. Peculiar. 



fodiens, Pfr. Also occurs in Philippines. 



Cochlostyla * satyrus, Brod. Peculiar. 

 Cyclotus euzo7ius, Dohrn. Peculiar. 



sordidus, Pfr. Said to occur in China and Cochin China. 



Opisthopoms quadrasi, Hid. Peculiar. 



' As laguiuB, Hid. This variable species appears to be confined to Balabac 

 Palawan, and Busuanga; Hidalgo (Journ. de Conch, ser. 3, xxvii. p. 109) cites 

 it also from Luzon, but I think this must be a mistake. 



^ As the var. graelki, Hid. 



' Including the varieties palawanica, Pfr., laguncB, Hid., doriw, Dohrn, and 

 ■palumha, Souv. Cuming gives monochroa from Tablas, which I think is a 

 mistake. Dohrn considers the occurrence of dorim in Borneo very doubtful. 



^ Including the varieties ^ra«/&i, Hid., palavanensis, Pfr., and librosa, Pfr 



a 



