PHILIPPINE MACROUROID FISHES—GILBERT AND HUBBS. 379 
G. CHINA SEA IN THE VICINITY OF HONGKONG. 
Three of the species obtained here—namely Hymenocephalus 
longiceps, H. nascens and Ventrifossa nigrodorsalis, occur through- 
out the East Indian-Philippine region, while the fourth, Zymenoce- 
phalus striatissimus, belongs to the typical subspecies found also off 
Japan, Formosa, and eastern Luzon. 
Iv. SYSTEMATIC DESCRIPTIONS. 
Family CORYPHAENOIDIDAE. 
Subfamily BATHYGADINAE. 
Genus BATHYGADUS Giinther. 
A detailed study of the various species of Bathygadus has led us 
to conclude that all of the described species are valid, 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. cottoides and B. melanobranchus. 
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 LB. macrops. 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. 
filamentosus. 
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 OF THE GENUS BATHYGADUS. 
a. Orbit’ decidedly less than two-thirds the interorbital width; head exces- 
sively wide and cavernous; scales on mandible in a single series*; no 
(i iad SSR ga a Sa itl RN Le cg? to Ta A i (BATHYGADUS). 
b*. BWirst dorsal, pectoral and ventral fins without long filamentous rays, 
all being shorter than the head, 
c’. Interorbital width contained less than 8 times in length of head; color 
DIaekishtee- 2 aes es Le “ie Dae ee ela eo bowers. 
c’, Interorbital width contained more than 3 times in length of head. 
ad. Ventral fins inserted in advance of pectorals; the distance from 
anus to base é6f ventrals greater than postorbital length of head; * 
coler blackish brown. 
1 With the single exception of B. dubiosus Weber, which seems to be identical with B. 
filamentosus. 
* Extreme length between orbital rim on each side as distinguished from diameter of eye. 
®* Not verified in B. cottoides. 
‘Verified in B. cottoides from Giinther’s figure. 
