208 BULLETIN OF THE BUREAU OF FISHERIES. 
The first thing to be noticed is the general similarity in the food. The Hawaiian 
nymphs ate mollusks, beetles, flies, bugs, erustacea, odonates, and protozoa, the same 
as the Fairport nymphs. Many of the food species were different, as would naturally 
be expected, but they belong to the same families and sometimes to the same genera. 
Unlike the nymphs at Fairport, those at Honolulu ate bees, ants, and adult Chiro- 
nomids, mosquitoes, and flies. These land insects undoubtedly dropped into the 
water before they were captured, and Warren has suggested that since the Hawaiian 
streams and pools contain but few aquatic insects, while the dragonfly nymphs are 
numerous in many localities, the latter must obtain a part of their food from land 
insects that fall into the water. This idea induced him to try them with all kinds of 
land insects, and he found they would eat anything he offered. (See p. 206.) 
Tadpoles also appear in their diet, probably due to the scarcity of insect food just 
mentioned and also to the fact that the frogs and dragonflies are compelled to breed 
in restricted bodies of water, so that they are brought into close contact. Another 
result of the scarcity of insect food is that the majority of the nymphs fed upon a single 
Chironomid species, Chivonomus hawaiiensis, and upon the crustacean genus Cypris. 
If the food had been more plentiful there would have been a greater variety in the diet. 
Consequently the extreme variety in the food of the Fairport nymphs is a good indication 
of the richness of the food supply. 
Foop oF Nympus From Ituica, N. Y.—A table has been made out by Miss Lyon 
(1915) showing the food of 36 nymphs, distributed among 3 Aischnid species, 2 Gom- 
phids, 4 Libellulids, and 4 damselflies. Cascadilla Creek, from which the nymphs 
were obtained, flows along the southern border of the Cornell University campus at 
Ithaca. The nymphs were collected at intervals from November to July, thus covering 
nine months of the year. 
For the sake of convenience, her figures have been reduced to the same method 
of treatment as used in the statement on page 2or. 
Foop Founp 1n ALIMENTARY CANAL OF 36 ODONATE NympHS FROM CASCADILLA CREEK, ITHACA, 
N. Y., EXAMINED By M. B. Lyon. 
Mollusca: Physa, partly digested............ 1 | Crustacea—Coatinued. 
REGTES: VCISCHS SD. ccc cece sce he cele eee 2 Cy clopsy SPioct. oe can ace erecra ete ete ranrerers 2 
Diptera: GYPEIS Hp ees ces ere eee see enters rete 2 
Chironomid) larvee et 2: ORS POORER 24 Undetermined Merl OF. BRP. I 
Mosquito larve, Anopheles,sp........... 1 | Odonata: 
Undetermined larva..................... I Libellulid, sp., ty Mpls... piper e nietiatale I 
Hemiptera: Ophiogomphus, sp., nymph.............. I 
(Woy re eke ymeeyols\5 b SAG y yu Oe eebUICS ae 6 Ipamselpy. wiym physi. oc ses wil eels lee 9 
Corixaladdlts: 2 eae cee crs: least: flats 2 | Arachnid: 
Ephemeride: MITE LS 5.cs selasen cate eee eR ees Meee 2 
Heptagenia;spaivuiae- eerie ssati selene 4 iMacrobiotus, Spine. sfeceeoehs on ere ewes I 
Hexagenianspiisteiestaer recite ee rt} Alge: 
Canis Spinks <q2ch ie sca bene arti eee I Diatoms:,!. cc sk Sour Mee hinsoonlae 5 
Undetermined mayflies................-- 2 Closterium, sp) saece. face sertn-oriteeee B 
Crustacea: CEdogonium, Spe. ./-:.-65-.. 4 hs tees I 
Hayalella, sp.) ica... areas ae 5 
Diaptomus; Sp./.2.)....- oe eee ae 2 
Miss Lyon’s investigations showed that while Chironomids, mayflies, and odonates 
were eaten voraciously throughout the year, the crustacea and Hemiptera were con- 
