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PACIFIC SCIENCE, Vol. VII, April, 1953 
simplest in the family. A single row of large, 
round, tenaciously adherent scales is present 
over the lateral-line tube; each scale is pierced 
by a median pore only. The scales over the 
remainder of the body are very small, round, 
and deciduous. The anal fin has comparative- 
ly few rays. 
Paralepis, which is restricted to a few species, 
is undoubtedly a derivative of the Magnisudis 
line of evolution. These fishes resemble Mag- 
nisudis and differ from all the remaining para- 
lepidids in the short, heavy head and body, 
anteriorly free supramaxillary, long anterior 
teeth on the gillrakers, and low number of 
anal rays. The relationship is, however, not 
really close, since Paralepis differs from Mag- 
nisudis in several important characters. The 
gillrakers are shorter and more spine-like than 
in Magnisudis, and there are numerous teeth 
on each raker. Only a few anterior teeth on 
each gillraker are long, and all the posterior 
teeth are very short and needle-like. The 
tongue is long, farther back in the mouth than 
in Magnisudis, and the gillrakers do not ex- 
tend as far forward on each side of the tongue. 
The lateral-line structure is more complex. 
There are one and one-half or two rows of 
caducous scales over the lateral-line tube. In- 
stead of having but a single median pore, each 
lateral-line segment is often pierced above and 
below by another pore. In most species the 
upper scale row over the lateral line is pene- 
trated near the lower margin by the upper 
pore, and the lower scale row receives the 
middle and lower pores, although there is 
extreme variability in pore structure and a 
tendency for the reduction in number of pores 
piercing the lateral-line scales. The body scales 
are longer than broad, the same size as the 
lateral-line scales, and extremely caducous. 
There is little variation within the genus Para- 
lepis; except in the case of the inadequately 
known P. elongata Brauer, the species are very 
closely related and somewhat difficult to tell 
apart. 
The most specialized of the scaled genera 
is Notolepis, which approaches Lestidium more 
closely than any other scaled form. The snout 
is prolonged and pointed, and the body is 
more elongate and less deep than in Paralepis. 
The teeth in the adults are not lacking or 
reduced as in the other scaled genera but are 
fairly long and well developed. They are dis- 
tinctly arranged in two or three rows, the 
outer row of short, fixed teeth, and the inner 
series of long, hastate, depressible canines. 
The lateral line is essentially similar in struc- 
ture to that of Paralepis but has more pores; 
the upper scale row is sometimes peculiarly 
modified, being notched to receive the large 
upper pore instead of being pierced by this 
pore series. The body scales are round, over- 
lapped for most of their length, and are the 
same size as the lateral-line scales. The teeth 
on the gillrakers are reduced in length and 
consist of numerous tiny teeth in oblique 
rows on each raker. The pharyngeal teeth are 
reduced in number. It is known from Ege’s 
investigations that the scales tend to form 
late in life in at least one of the species (N. 
rissoi), and it is very probable that there is a 
tendency for the suppression of scales in this 
group. The three species of Notolepis are wide- 
ly separated in distribution: N. rissoi from the 
North Atlantic, N. coruscans from the North | 
Pacific, and N. coatsi from the Antarctic. The 
two northern species are much more conserva- 
tive in form than is N. coatsi, which has an 
extreme development in dentition, gillrakers, 
and lateral line, and these two species are 
separated in the new subgenus, Profundisudis. 
The next evolutionary step appears to in- 
volve a greater development of the elongate 
form and dentition, an important reduction 
in the number of gillraker teeth, loss of all 
scales, further specialization of the partly os- jj 
sified lateral-line segments into characteristic !j 
scale-like structures, a wide variability in the ii 
position of the pelvic fins in relation to the |j 
dorsal fin, and a wide range in the number of I 
anal rays. The most generalized genus of this 
group is Lestidium which corresponds to group 
II of Ege (1930: 7). 
Lestidium can be distinguished from the 
