SHORTKR AKTK^.KS AND DISCT^SSIOX 



'IIOMIXO ' BEHAVIOR IN (IIITOX' 



of the facts leading iis to ascribe to Chiton a certain deprree of 

 "homing" behavior. 



2. It was noted by Heatli (1899, p. 4), on the Californian 

 coast, that tho adult /.^cluiochifon mag dale nen sis is found dur- 

 ing the dav mi(lff houldns between tides, but that at night the 

 mollusc coiius (Mil t(. tci'd MM seaweeds growing upon the rocks, 

 retiring to (bii'k sit u;it inn-, nlier sunrise. Species of Mopalm, 

 and Cnfptorlnfoi>. were tMiiiid K, '-n'mam out on their feeding 



CpecKsai. 1.1. ... Ml piiotuii .t also (^lozier, 19196), 



but some iH^drlul.ss ( (.iiiiinu.uslx oc.upx situations brilliantly 

 illuminated (cf. Heath. 1«99, p. 4; Plate, 1901; Pelseneer, 

 1906, p. 50). It has been shown elsewhere (Crozier and Arej, 

 191h, ArcN and Crozier, 1919) that \oung induiduals of Chiton 

 tuherculatus are photonegative to ordinary daylight, the older 

 ones photopositive. This matter of photic in-itabilitv is inti- 

 mately concerned with certain diurnal moyonicurs simulating 



Heath (1904) was of the opinion that the bilateral larval eves 

 of some chitons, persisting as they do well into postlarval life, 

 until the shell plates become opaque, might be functionally im- 



