442 BULLETIN 100, UNITED STATES NATIONAL MUSEUM. 
23. COELORHYNCHUS THOMPSONI, new species. 
Ty pe-specimen.—Cat. No. 78214, U.S.N.M., a mature female 106 
mm. long to anus, dredged at Albatross station 5363, ata depth of 180 
fathoms, in Balayan Bay, on the southwest coast of Luzon. 
Four other specimens were obtained: 
: Bottom | Number 
Albatross 3 | Depth in ‘ 
att Locality. : tempera-| of speci- 
station. fathoms. ane ens 
° 
5110:| ‘China: Séa, of southern bnz0n- os. ohne eee oe oe eee 135 59. 0 1 
5118 | Verde Island Passage, Luzon............- Sake ot ersodes baaee Soe hd Beene ate 1 
5518 | Off northern Mindanao.......- Rae ee oe se | 200 54.0 2 
The two specimens from station 5518 show certain differences 
from the typical specimens, and are referred with some doubt to 
the same species. It is of interest to note in this connection that 
all of the 14 specimens of the preceding species, C. quincunciatus, 
were dredged at six stations among the islands between the locatities 
at which typical and aberrant specimens of C. thompsoni were ob- 
tained. The aberrant specimens differ in the rougher spination 
of the scales, in the fewer pyloric caeca (14 instead of 22), and in 
the shghtly narrower interorbital and suborbital. 
Fin-rays—first dorsal, IT, 9; pectorals, 15-16 (17 or 18); ven- 
trals, 7. 
Greatest depth of body, 2.2 (2.3 to 2.4) in head; width across pec- 
toral bases, 3.3 (3.8 to 3.7). The sides of the snout gradually con- 
verge forward toward the very sharply acuminate tip, which, 
higher than in C. argentatus or C. quincunciatus, lies on a horizon- 
tal passing through the eye above the lower margin of the pupil. 
The greater convexity of the dorsal outline of the snout, together 
with other characters, renders the physiognomy of this species very 
different from that of C. argentatus and C. quincunciatus, which 
are quite similar in their general appearance. The preocular length 
of the snout is contained 2.2 (2.1 to 2.15) times in the head; preoral 
length, 2.35 (2.23 to 2.8); width of snout at front of orbits, 3.5 
(3.5 to 3.6); width of snout at anterolateral angles (a point below 
the front of the nasal fossa), 1.5 (1.4 to 1.55) in the distance 
anterior to that point (in other words, in the ethmoid region of the 
infraorbital ridge). The occipital ridges diverge strongly anteri- 
orly, but weakly posteriorly; the least distance between them is 
contained 2.4 (2.5 to 2.65) times in the interorbital width; from 
their terminations on each side a scaleless groove extends back- 
ward to the lateral line. The sharp postorbital ridge curves slightly 
downward behind the preopercular ridge; the subopercular angle 
i i 
“lo 
