65 
count, a diagram results that will materially aid in presenting 
the facts. (Vide appendix). 
It may be seen at a glance that the number of gas- 
trosteges varies from 132 to 179, thus indicating a difference 
of 47 somatic vertebra. Further inspection evidences that 
the specimens from the islands have the shortest bodies. If 
these are compared with specimens from Central Asia the 
opposite extreme of the distribution it is seen that they do not 
overlap in respect to this character, the gap of one vertebra 
existing at the numbers 146-147, However, in the immediate 
vicinity of this discrepancy there are ample records from the 
intervening mainland, that is the Ussuri Province and Korea. 
It is clear that the affinities of the Japanese specimens are to 
be found among those from China. The final point to be de- 
rived from this diagram is the fact that no lines of demarka- 
tion or grouping of the specimens exist. Such lines would 
necessarily be found were we dealing with distinct species, 
while their absence is proof that but one species is under con- 
sideration. 
VARIATION IN UROSTEGES. 
The urosteges exhibit a wider range of variation propor- 
tionately than the gastrosteges, the count being from 30 to 58, 
a difference of 28 caudal vertebrae. 
Examples. Minimum. Maximum. 
OUR EREUIOG: caveniet ca nciva tat cht teers uke , ve 182 30 58 
Mainland Specimens 138 30 53 
GOntraly ABIB ne Vewiars ca en 58 82 53 
Mastern Siberia 27 386 61 
IS OPE cris atonis Wet eer Cae 24 31 52 
Yangtse Valley 29 30 43 
US SPOClmens, arscvwk sive hese 44 41 58 
PE MOUIULO <eaawibin dh casi eG hE LEN RAT ST Noles 6 oe 6 41 52 
BLOM: Sa tate nv Vena warns ae Rie CELT ae 24 45 58 
PCO JORMIMGG reset ias ss Lid ie bse) p44 cds ous 2 46 46 
AV le eerie Ae i i wi Yin aceL Aa Hpi O46 RON 1 50 50 
COM aaa yp Sane ery La Kes UO ate ene see Oh 2 45 47 
Mbt hehe URES tee me he oe i oe en ee i 48 48 
DST BTTINELELE died a-.6 hi wk eenen yA 6 ooh EMG L 4 uaer ko hd 5 4] 50 
SB WB ULI Bi 4 dons ot erie CA Aa a Us OIE WEA ee Lc ee 8 44 46 
It occasionally happens that a few of the urosteges are 
entire. These undivided shields are regularly found close to 
the base of the tail. 
With 
a few entire 
Hxamples. Normal Shields. 
Otel NUIN BEL lias aaei deine tia is vs oleh cas 61 51 10 
WESC CE LOVINCG sii aiGer Mr vlas «rie rie reve’ 3 2 
PROTON. Gy ci kei vsae su ¥eeel os caus le coven ered ee 20 17 3 
PCC LLG eV acs wees wacie eet haa Carn ue ¢ Ear av a 20 16 4 
WDE: crits SiN W Nevaeh Ae IAA RRS S INA ONS Fay 18 16 2 
VARIATION IN SCALE Rows. 
Over fifty specimens have been studied for this character. 
They include material from seventeen localities in the eastern 
