235 
there is no co-ordination in the variation of these two fins. The per cent. 
of variation above or below the prevailing number in each case is so small 
that it may be regarded as purely accidental. At least it can be said that 
this fish in Turkey Lake has reached a stage of stable equilibrium as re- 
gards this character. 
DORSAL AND ANAL FINS. 
Dorsal. Anal. No. Dorsal. Anal. No: 
BLESS ge ee ae this caries Gee eee eoeeerte Pee ARAN oe [ODO Ua aie Seer ot rat JONAS ober a BOSebe 4 
TR Bae cece See Ii Anaccena saa seats DAPI G Gs eee eee: TG Retee nes iH 
il CEA ve apes Sones 1 WS SAP Saree OE aee (ME OT pete ea iG iets} owe, Sane ee 3 
ee Tira cote ee soar %°  INt Bee I 6% 1 
lt UA eae TSG e chon se eon od as 1g Bethe Sia hme ce eee 1 i Oy Ana eA ane 1 
it Cs ee eS eaee i Ul reo Arata Bey Pa D lt Giger. ocaoeemacmane 1 
Halig Sofetee Ps 5 cea TRF ESS cea skesee 2 
The dorsal and anal fins of seventy-two specimens from Tippecanoe 
Lake were examined and the results obtained are shown in the following 
tables: 
DORSAL AND ANAL FINS. 
Dorsal Fin. No. Specimens. Anal Fin. No. Specimens. 
TUT Oe hs oe a a 64 HINES (erate nt sears gene mews eR Pi cas See 69 
ITT GRE dale <a OEE ea i ge Se ea TE SUA ESP ee Pe act PsP Renae ae 2 
IS. 8G d alstse eleew Sete cela eOeeke eee haere Sc ae aie Wrote ake tne ona oe Rte in AM re 9 1 aoe 
Il GUA 3 din DM aoe a Acar aeons ee anes 3 
DORSAL AND ANAL FINS COMBINED. 
Dorsal Fin. Anal Fin. No. Specimens. Dorsal Fin. Anal Fin. No. Specimens. 
NBG ocrtes atteds.e:ts NEA Bop don SeReeene 62 LER aes BGA see 1) Lye Aneta ber snoneeee 2 
NE ars cra rosette Sac ND ERC RESP a OR ones 3 Dir B eat See eee nee 17% 1 
Nile oncbaeties oo has IND ES. ene Sade dee 2 8h Tr OUGre comers ae 2 
A comparison of these tables with the preceding ones shows that the 
per cent. of variation in the Tippecanoe specimens is much larger than in 
those from Turkey Lake. However, the number in the one case is not 
sufficient for a definite conclusion. Leaving out of consideration the small 
rudimentary ray, which would not be noticed in an ordinary examination, 
and considering only those cases in which there is a variation of at least 
ohe complete ray from the prevailing number, the per cent. in the dorsal 
fin of the Turkey Lake specimens is 1.3, while in those from Tippecanoe, 
it is 7. The per cent. of Turkey Lake specimens, that have a variation 
of at least one ray from the prevailing number in the anal fin, is 1.1, while 
in the Tippecanoe specimens it is 2.8. 
