PHILIPPINE MACROUROID FISHES GILBERT AND HUBBS. 379 



G. CHINA SEA IN THE VICINITY OF HONGKONG. 



Three of the species obtained here — namely Hymenoeephalus 

 longieeps, H. nascens and VentHfossa rdgrodorsalis, occur through- 

 out the East Indian-Philippine region, while the fourth, Hymenoee- 

 phalus striatissimus, belongs to the typical subspecies found also off 

 Japan. Formosa, and eastern Luzon. 



IV. SYSTEMATIC DESCRIPTIONS. 



Family CORYPHAENOIDIDAE. 

 Subfamily Bathygadinae. 



Genus BATHYGADUS Gunther. 



A detailed study of the various species of Bothy gadus has led us 

 to conclude that all of the described species are valid, 1 and further, 

 that, in so far as known, they are of localized distribution. In ad- 

 dition to the two species we are now describing, we have examined 

 all of the twelve species hitherto known with the exception of two : 

 B. eottoides and B. melcvnobrancTms. 



The species of Bathygadus form a well-graded series, by which 

 those with excessively wide and cavernous heads are connected with 

 those having comparatively firm heads. At the two extremes of this 

 series stand B. bowersi and B. macro ps. These two species are of 

 very dissimilar appearance, but their reference to the same genus 

 can be justified by the existence of such intermediate species as B. 

 ftletmcntosus. 



An attempt has been made in the construction of the following 

 key to indicate the mutual relationships of the species. 



KEY TO THE KNOWN SPECIES OP THE GENUS BATHTGADUS. 



o\ Orbit 2 decidedly less than two-thirds the interorbital width ; head exces- 

 sively wide and cavernous ; scales on mandible in a single series 3 ; no 



barbel (bathygadus). 



b\ First dorsal, pectoral and ventral fins without long filamentous rays, 

 all being shorter than the head. 

 c\ Interorbital width contained less than 3 times in length of head; color 



blackish bowersi. 



c 2 . Interorbital width contained more than 3 times in length of head. 

 d 1 . Ventral fins inserted in advance of pectorals ; the distance from 

 anus to base of ventrals greater than postorbital length of head : 4 

 color blackish brown. 



1 With the single exception of B. dubiosus Weber, which seems to be identical with B. 

 ftlamentosva. 



- Extreme length between orbital rim on each side as distinguished from diameter of eye. 



3 Not verified in B. eottoides. 



4 Verified in B. eottoides from Giinther's figure. 



