Porstlarval Scombroids from the Central Pacific — STRASBURG 
181 
length of gracilis lies significantly distant from 
this range, and the two forms are therefore 
considered distinct species. 
Because not all postlarvae in the 10.0-17.4 
mm length range have acquired the adult fin 
ray complement, it is necessary to list meristic 
and length data conjointly in Table 3. The 
number of dorsal and anal fin rays increases ir- 
regularly with size. The pectoral, pelvic, and 
caudal fins and the branch tostegal rays show 
little or no meristic variation. Except for one 
specimen with 13 rays on one side and 12 on 
the other, the pectoral was constant at 12 rays. 
There were 7 branchiostegal rays and 9 + 8 
principal caudal rays, the latter being difficult 
to count because of damage or nonattainment 
of definitive shape. In all 13 specimens the 
pelvic fins are represented by a pair of stout 
denticulated spines, in agreement with Maul’s 
findings (1948:42) but not with Tucker’s (1956: 
79-81). The latter, working with a ’'completely 
skinned” paratype, observed "Ventral fin I-I; 
a narrow scale-like spine and an external split 
ray twice as long.” Palmer and Marshall (in litt.) 
have re-examined this paratype but failed to 
find the external split ray, observing only the 
scale-like spine and the pelvic bones. I suggest 
that Tucker’s "ray” was in reality the splintlike 
pelvis, perhaps loosened in its muscular bed by 
the force which skinned the fish. In my speci- 
mens the attenuate pelvis bears a marked re- 
semblance to a soft ray and is, coincidentally, 
just twice as long as the pelvic spine. 
The most distinctive feature of the 10.0 -mm 
postlarval Diplospinus is its relatively great 
depth at mid-length. As shown in Figure 8, this 
is caused by a ventral distension of the belly by 
the elongate pelvic bones, a condition reminis- 
cent of the Balistidae and Monacanthidae, except 
that in Diplospinus the pelvis extends poste- 
riorly. The great depth of Diplospinus is quite 
different from the narrow belly of Lepidopus at 
Fig. 6. Nealotus tripes 41.5 mm in standard length. The eyes are lacking in this specimen, but have been 
drawn as they appear in another of about the same size. 
