SHAD. 
987 
Clup 
e a f i n t a. 
C l u p 
e a a 
l o s a. 
9 
d 
d 
? 
c? 
9 
9 
d 
9 
Length of the body expressed in millimetres. - 
121 
284 
302 
348 
393 
147 
147 
321 
358 
385 
Base of the anal tin in % of the length of the body 
14.7 
16.o 
13.9 
14.6 
16.o 
16.0 
18.i 
17.o 
17.6 
17.i 
„ „ ,, „ „ „ » „ „ ,, „ ,, head 
62.8 
71.5 
60.8 
64.5 
72.o 
61.3 
75.8 
85.i 
74.i 
79.5 
„ „ ,, „ „ „ ,, „ „ distance between the anal tin and the tip of the snout 
21.8 
24.3 
20.7 
21.i 
24.0 
22.6 
27.2 
29.6 
26.9 
26.i 
,, ,, „ ,, postabdominal length 
63.6 
75.8 
56.7 
61.8 
72.4 
70.3 
86.4 
87.6 
80. o 
79.6 
„ ,, dorsal fin in % of the base of the anal fin 
93.8 
80.2 
105.9 
92.7 
91.7 
80. o 
74.5 
74.2 
79.3 
75.7 
Length of the maxillaries ,, „ „ „ ,, 
78.6 
68.7 
80.9 
71.5 
65.i 
71.i 
63.6 
53.8 
63.5 
56.5 
„ ,. „ lower jaw — „ „ „ „ „ „ „ >, 
95.5 
86.8 
98,s 
90.8 
84.i 
93.3 
84.2 
68.5 
74.6 
75.3 
„ ., „ pectoral tins ,, ,, ,, ,, ,, 
109.4 
96.7 
102.3 
99.c 
90.5 
103.5 
90. o 
75.o 
84.i 
80.3 
.. ,, ventral fins , „ „ ,, ,, 
72.4 
61.5 
68.i 
63.7 
54.7 
60. o 
58.o 
45.o 
52.4 
50. o 
Least depth of the tail ,, ,, ,, ,, ,, ,, 
57.8 
46.i 
57.i 
52.o 
48.5 
53.3 
46.8 
39.9 
42.8 
38.8 
The rule is clear: the young and the males have 
the shortest anal fin, and the Allice Shad is charac- 
terized by the long base of its anal fin. But in this 
character the young male of the Allice Shad — a Medi- 
terranean specimen 147 mm. long and sent here by 
Hedenblad — ranks beside the female T waite Shads, 
and is so closely approximated to them that the dif- 
ference is useless as a specific character. The character 
is, however, not without importance, for we find on 
comparison that in most of the relations the base 
of the anal fin is much shorter in male Twaite 
Shads than in Allice Shads less than half as long. 
A development of form, determined by the female 
characters, has evidently advanced from finta a to alosa; 
but this development has not yet attained such defini- 
teness that true species can be distinguished. The spe- 
cific character first pointed out by Troschel, the dif- 
ference in the number of the gill-rakers — greater in 
alosa (fig. 249, h) than in finta (fig. 249, a) ■ — is im- 
paired by the same indefiniteness. Steindachner and 
Moreau showed that their number increases with age, 
whereupon Lilljeborg remarked with justice that the 
character can only be employed in comparisons between 
specimens of about equal size. The case appears to be 
the same here as in the Gwyniads (see above), where 
we also failed to arrive at more than variety distinc- 
tions by the aid of the differences in the gill-rakers. 
And even if we could prove that the character derived 
from this source agrees in our European Shads with 
other characters 6 , the North American Shad apparently 
baffles our systematic calculations, for it is fur- 
nished, according to Jordan and Gilbert, with the 
gill-rakers of the Allice Shad, but externally resembles, 
according to Todd’s figure in Brown-Goode (1. c.), the 
Twaite Shad. 
The form and texture of the scales (fig. 245, b) 
we have described above. They are more firmly at- 
tached to the skin in most cases than in the Herring. 
The irregularity of their arrangement and the absence 
of a lateral line render it difficult to compute their 
number with certainty. The number of spiniferous 
scales at the ventral margin is 37° in all the specimens 
examined by us, 23 or 22 in front of the ventral fins 
and 14 or 15 behind them. Elere too these scales are 
covered to the greater part of their extent by the 
nearest lateral scales. 
The coloration is essentially the same as that of 
the Herring. The dark (blackish blue) spots charac- 
teristic of the subgenus Alosa, set in a straight or an 
interrupted (zigzag) row on the sides of the body, the 
largest — sometimes as large as the eyes, but commonly 
smaller — first, are most usual in young specimens. 
They formerly ranked as a character of the Twaite 
Shad, but are of very irregular occurrence even in this 
variety. Our figure (Plate XLIII, fig. 2) also shows 
that they may be quite numerous in the Allice Shad; 
and Fatio relates that, on boiling adult Allice Shads 
from the Rhine in order to prepare their skeletons, as 
many as 15 spots appeared on the sides of the body. 
“On the sides of the head too,’’ writes Kroyer of the 
Twaite Shad, “a black spot may sometimes be seen 
above the preoperculum”; and in one of our Twaite 
a Or perhaps from the North American Clupea chrysochloris , with its still shorter anal fin, unless this form be an instance of retro- 
gression in development. 
* Lilljeborg has adduced the different form of the tip of the snout and the greater number of the scales in alosa (see above). 
0 37 — 42 , according to Valenciennes. 
