124 
bass have relatively the widest mouths of all. It is also to be note 
that the large-mouthed bass commenced to take fish when an’ ineh 
and a quarter long, and the small-mouthed species not until it 
reached a length of two and a half inches. 
It will also be observed that Entomostraca are least abundant in 
the food of the small-mouthed black bass and the rock bass—species. 
found usually in swift and shallow water, when of this size. The 
importance of water-bugs (Corixa) to the first three species of this 
table is evident. . j 
From the table of adult food we find that these commencing pecu- 
liarities of the preceding table become here more prominent. All 
the Entomostraca of this table, except insignificant traces, now 
appear in the food of Pomoxys; the molluscan food of Kupomoti 
is nearly five times that of any other genus; and the ratios of fish 
food, running from eighty-six per cent. down to nothing, when -ar-. 
ranged in a series, are seen to correspond, with curious exactness, 
to a series of the species themselves arranged according to the rela- 
tive sizes of their mouths. 
I was disappointed in being unable to find any food characteristics 
corresponding to such minor differences in the lengths of the oill- | 
rakers of the anterior arch as appear in Lepiopomus, Apomotis, 
etc., on the one hand, and Xenotis and Eupomotis on the other, 
If such peculiarities exist, they can probably be determined only by 
taking at one time and place a number of specimens of unlike 
character in this particular. 
While I believe that the generalizations made above will hold) 
good, at least for fishes of similar form and internal structure 
among the Acanthopteri, I do not wish to be understood as extend- 
ing them at present beyond this order. Doubtless, while the char-. 
acters mentioned must assist greatly in determining the food of a 
species a priori, they are not by any means sufficient for this pur- 
pose when taken by themselves. The discussion of other features, 
external and internal, bearing upon this subject, must be postponed > 
to a later period of the investigation. 4 
rt! 
TasLe oF Foop or Youne Centrarcuipm. (One inch and under.) 
| 
eal Hi] a | | 
‘ | HO leo). = 5 B ee Be age PS ° nc a 
Bebe 0 on SIN Me clara am iead ome Fy ng a ge sto en 
> Oo jno, = iS = = CH arian He 
1 a os n Bf: /o- as 5 
POS Ce alee © + ' fap, fqumliRee htt ' = 
Ogee ioe mM ch ; Th ‘ mn ’ 5 
ea ok hee = ; ote : = 
fee RO" |e 2 So , ‘ . ‘ ' 
Sse eC eeseenecireeeeeee ea RD 
Number of specimens.......... Sista 3 2 1 bls 5 3 
1 BINB ECTS. 150 acto. Sie 2, ate ee ane RRL 02 nr) ee ae 24 281s tase 
1. PDibiert.: Ary ie) .os oe |e tae hese Us) aR ae 01 ree. a1 psig ae ee 
Chirosiomus 7.08.0: Toni eee es U5) s2ees (1 Salone 21} QS ie eo cee 
2» CELE DICK Rue” Ale eee UNE eee [ome slenees (tly ee OL Secrs Y cil hie Seas alcove 4 oer ee a 
Uoriza AVON eS) Fe ol we eae a a Oe ee a a Meee ee Ss eee 
3. Neuroptera (larvee)..........|...... hg DA: | Staal aeee teal Suet hers! 03 se 
/ ARAOHNIDA (Hy drachna)..- 40... ee... eee ee 04 Oe Sea es 
Lil ORUSTA CHA Ste io cee 100)... 61 100 98 59]... 75 72) 100 
Tatradecapoda:.., .«.¢a. 6 OF) eee ee), sei a | a? He 02] .. OL Leo eee 
Entomostracs 2.6 Oe 93) Sves 61 100 938 yd (aslo 71 72) 100 
Cladocera os...04.b.cne... =. 87} ese 58 70 03 Bledel ke 49 88 
Ostracoda..i, 547 Sie ae ete || Oe Aaa ee ae mee” PA AS 
Copepoda con ae ee U6]. ... 03 30 95 Pi eget ae 38 23 22| 93 
Tees Aare eo kee 
