PHILIPPINE MACROUROID FISHES GILBERT AND HUBBS. 377 



region consists largely of a partially inclosed cup, broken up by 

 islands to the northward, and communicating with more open bodies 

 of water only by narrow channels, much shallower than the depths 

 of the Jolo (Sulu) Sea, which in consequence are rendered peculiarly 

 warm. The temperature records of depths greater than 400 fathoms 

 vary little from 50° F., and nowhere was the temperature found to 

 fall as low as 49°, although depths of over 1,000 fathoms were in- 

 vestigated. 1 



At the northern end of the Philippine subregion, in the China Sea 

 off southern Luzon, it was found that the temperatures do not re- 

 main warm at greater depths. Here the fauna resembles, in general, 

 that of the moderate depths to the southward, and as it contains no 

 additional northern elements we consider it a derived portion of 

 the Philippine fauna. It is characterized particularly by the ex- 

 clusive or nearly exclusive occurrence of Coelorhynchus velifer, C . 

 macrolepis, and C. carinifer. 2 Of the other species peculiar to the 

 Philippine subregion, this northern district shares with the south 

 only C oelorhynchus thompsoni, Hymenocephalus strlatissimus torvus, 

 and Ventri fossa lucifer (one specimen), fishes inhabiting the mod- 

 erate depths. The remaining fishes inhabiting the China Sea off 

 southern Luzon are not among those peculiar to the Philippine sub- 

 region. 3 



To the westward of Japan there lies a sea (Sea of Japan) which is 

 surrounded by a rim which is not at any point depressed as much 

 as 100 fathoms below the sea level. The straits which connect the 

 Sea of Japan with the Pacific are thus above the normal bathy- 

 metric range of Macrouroid fishes. This Sea of Japan is geographi- 

 cally somewhat analogous to the area of the Philippine subregion 

 just discussed, but faunally it differs strikingly in the fact that 

 Macrouroid fishes " were not to be discovered in the Sea of Japan nor 

 the Gulf of Tartary, although numerous and successful hauls of 

 the trawl were made at the appropriate depths " ; but " they were 

 found in the Okhotsk Sea and everywhere to the eastward of the 

 islands." 4 



C. THE FAST COAST OF MINDANAO. 



The only species obtained in the Pacific Ocean off eastern Min- 

 danao is Hymenocephalus barbatulus, unknown elsewhere, but closely 

 related to H. papyraceus of Japan. 



1 An unusually heavy degree of parasitism noted among these fishes is probably to be 

 correlated with the lack of currents in this comparatively warm inclosed sea. 



2 The distribution of Malacoccphahis lusonensis differs from any of the others : it is 

 Known from three specimens from southern Luzon, one from western Luzon (taken with 

 lntergrades between Hymenocephalus s. striatissimus and H. s. aegcr), and one from 

 eastern Luzon. 



3 Two species, known also from the East Indies and from off eastern Luzon, are known 

 from the Philippine subregion by a single specimen : A specimen of Gadomus introniger 

 was dredged off southern Luzon, and one of TAonurus pumiliceps off western Luzon. 



*■ Gilbert and Hubbs, Proc. U. S. Nat. Mus., vol. 51, 1916, p. 135. 



