Japanese Gempylidae — MatsuBARA AND IWAI 
207 
supposed differences (diameter of eye 4.8 and 
interorbital space 4.6 in head in R. furcifera). 
In his description of R. furcifera, Waite 
mentioned ’'Ventral IV,” but we think this 
is probably a misprint for "Ventral I.” 
Finally, we searchingly examined the de- 
scriptions of these four nominal species by 
various authorities and compared the other 
important characters as described with our 
specimens without finding any characteristics 
that would enable us to separate these species. 
Nealotus Johnson 
N e alotus ]ohmon (1865: 434— type N. tripes 
Johnson). 
In general physiognomy, this genus closely 
resembles Promethichthys Gill but appears to 
differ in having a dagger-shaped spine behind 
the vent, followed by a minute spine; a 
straight lateral line; rather large nonimbricate 
scales; and a single short (dorsal) branch 
running upward and backward from each pore 
in the lateral line (Fig. lOA). Promethichthys 
lacks the isolated free spines behind the vent; 
its lateral line descends sharply downward 
and backward on the anterior part of the body 
(Fig. IC); its scales are definitely imbricated 
and cover the whole body and head except for 
the snout, jaws, throat, and interorbital space; 
and each pore in its lateral line has short upper 
and lower branches running obliquely back- 
ward, except on the anterior curved part, 
where the pores have only an upper branch, 
as in Nealotus (Fig. lOB-C). 
Nealotus tripes Johnson 
Figs. lOA, 11, 12 
Nealotus Johnson, 1865: 434; Gunther, 
1887: 35; Goode and Bean, 1895: 199; 
Jordan and Evermann, 1896: 881; Smith 
and Pope, 1906: 465, fig. 1; Jordan, Tanaka, 
and Snyder, 1913: 123, fig. 89; Jordan and 
Hubbs, 1925: 221; Norman, 1930: 351, 
fig. 41; Fowler, 1936: 634; Kamohara, 
1940: 99, fig. 47. 
MATERIAL DESCRIBED: No. 13957, 199 mm. 
in standard length (237 mm. in total length). 
Fig. 10. Lateral line in two species of Gempylidae. 
A, anterior part in Nealotus tripes; B, curved part in 
Promethichthys prometheus; C, anterior section behind 
curved portion in P. prometheus. Drawn by authors, 
off Owase, Kumano-Nada, October 2, 1950. 
Originally described from one specimen 
taken at Madeira, this species has since been 
reported as follows: one specimen each from 
between the Bahamas and Madeira (Gunther), 
from near Hamashima, Japan (Smith and 
Pope), and from near Misaki, Japan (Jordan 
and Hubbs) ; and two specimens from off the 
west coast of middle Africa (Norman). 
D. XX, I, 17+2; A. II, I, 16+2; P. 12; 
V. I; Br. 7. Head 3.56 in body length; depth 
6.63; width 12.75. Snout 2.43 in head; eye 
5.00; interorbital 5.18 (bony width 5.65); 
upper jaw 2.03; depth of caudal peduncle 
5.53; pectoral 1.75; ventral 12.15; longest 
(5th) dorsal spine 3.63; longest (4th) dorsal 
soft ray 3.27; dagger-shaped spine behind 
