PHILIPPINE MACROUROID FISHES GILBERT AND HUBBS. 543 



55. ? MALACOCEPHALUS LAEVIS (Lowe). 



Malacocephalus laevis Weber, Fische cler Sifro#fl-Expedition, 1913, p. 166. 



Doctor Weber has kindly reexamined his material for us, and has 

 made some measurements on the head which indicate that his speci- 

 mens are not referable to M. luzonensis. The measurements referred 

 to are as follows : 



Siboga station 38 38 314 



Total length 300 mm. 321 us:; 



Preocular length of snout 15.5 tarn. 15 11 



Preoral length of snout (from ftont of premaxillary)__. 12 nun. 12.5 13 



Postorbital length of head 27 mm. 23.5 22 



Whether these specimens are really referable to M . laevis is not evi- 

 dent. We have no specimens of that species. 



VENTRIFOSSA, new genus. 



Type-species. — Coryphaenoides garmani Jordan and Gilbert. 



In the synopsis of the genera of Macrouroid fishes, which was in- 

 cluded in our report on the fishes of this family from Japan, 1 we 

 separated out a group of species 2 (e) distinguished by the number of 

 branchiostegal rays (seven), and by the position of the anus (remote 

 from the anal fin). The genus Malacocephalus was next separated 

 from the other genera: Lionurus, Mataeocephalus, Trachonurus, and 

 Cetonurus. But in the description of Lionurus z it was noted that 

 nine species differed widely from the others, but closely resembled 

 Malacocephalus in the large subterminal mouth and other characters. 

 These species, together with two new ones which we are describing 

 in this report, further agree with M alacoce phalus in the ventro- 

 lateral extension of the gill-slit, which is continued forward to below 

 the posterior rim of the orbit. In Cetonurus, Trachonurus, and 

 Mataeocephalus, as well as in the other species which we referred to 

 Lionurus, the gill-membranes unite below the ridge of the preopercle 

 or thereabouts, except in certain aberrant species like pumiliceps, in 

 which the whole ventral region of the head and trunk has migrated 

 forward, producing a very peculiar physiognomy. 4 In all the species 

 of Malacocephalus and Ventrifossa the length of the upper jaw is 

 contained decidedly less than 3 times in the head, while in all other 

 species in the group of genera under discussion, the length of the 

 upper jaw is contained about three times (Lionurus stelgidolepis. 

 Trachonurus villosus) or more than three times (usually much more} 

 in the head. 



iProc. U. S. Nat. Mus., vol. 51, 1916, pp. 135 to 214. 



2 In the listing of the species we erroneously referred to V. nigromarginata as L. 

 nigromaculatus. 



3 Proc. U. S. Nat. Mus., vol. 51, 1916, p. 192. 



4 Owing to the intermediate position of several species, we are unable to define or 

 delimit a group based on pumiUceps and its nearest allies. 



119404—20 12 



