130 



Didjilniini.s was tlu> mily other form tluir siunvcd any tt'iuU'ncy towant ;1 

 considerable surface increase after midniglit, but its morning increases 

 were much smaller than those of the evening-. Then. too. moonlight had 

 no appreciable effect upon the diui'nal movement of any of the Crustacea. 



1. There was c()m]>ai'ati\(>ly little chan.iie in tlie (luantity of plankton. 



2. IMui'iial movenieiil was sliown liy Kii'ischniii, IHa ii/oiiiiis. ('j/vloitii. 

 Ddplnini lii/aliiKi and rclrociirni hinnlnniosuniu. Lcptodai'ii. and ('ontJird 

 larvie. 



3. These various forms reaclu'd a maximum at the surface al)out S 

 p. m. 



4. Tight is a very important factor in tlie movement of nidptniuiis, 

 Ci/clops. and Ihi/iliiiiu Innirnid and rctnii-itrni. It is, apiiarently, not so im- 

 ]M»rtant a factor in liie movement of ilplxvlntni. DdjiJuiid iniUcdfid. Lrptd- 

 (lard. and Cnnlliid lar\a'. 



5. Diin-n.MJ movement was not alfected by moimliglit. 



LlTKUATruK (TTED. 



lUanc. ISilS. Le I'lankton nocturne du Leman. II. I'danc. Arch, des sci. 



])liysi(|. et nal.. '1'. d, ISPS. 

 Fordyce. lPni>. Tlie Cladocera of Nebraska. Cliarles Fordyce. Trans. 



Amer. Micro. Soc. \dl. XXll. p]). lT.l-174, li)(K>. 



