226 A. T. CAMERON AND C. H. o'DONOGHUE. 



so narcotized as with benzene. The response was evident as a 

 flick back of head and antennae. The animals ceased to respond 

 after 90 minutes' immersion. They were transferred to fresh sea- 

 water and during recovery gave similar but slighter responses to 

 "darkness." 



4. Mollusca. Nudibranchia. Hcniiissenda opalcsccns. A spec- 

 imen was found on eel-grass. 



Camphor (resublimed, i : 16000) was tested on this specimen. 

 After an hour there was some appearance of a reaction to " light," 

 but none to "darkness." After n hours the animal was still just 

 alive. 



* 



50. Vcrtcbrata. Pisces. 



(A) Cottoid (sp.). Small fish, too young for identification, 

 about one inch long, caught in pools fiear low-water mark. 



Benzene (1:1500) was fatal in three minutes. Benzene (i: 

 3000) was fatal in less than 13 minutes. No responses to illumi- 

 nation changes could be detected. A (i : 5000) solution was fatal 

 to some animals in seven minutes. At this period in two cases a 

 definite reaction (flick of body) was obtained with "light," but 

 none was observed with " darkness." 



Phenol (i : 2000) was fatal to two of three animals in two min- 

 utes. The third was transferred to fresh sea-water and gave one 

 or two doubtful responses to light changes. 



Camphor (resublimed, i : 16000) was without effect. The fish 

 were normal after three and one half hours. 



(B) Plwlis onwtits. -Blennids caught at low tide amongst the 

 eel-grass. 



Benzene (1:3000). Two small specimens, about three inches 

 long, were almost narcotized in three minutes. They were trans- 

 ferred to fresh sea-water. No reaction to " light " was observed, 

 but several definite responses to " darkness " were obtained. After 

 12 minutes both animals were dead. 



Phenol (1:2000). Two similarly sized specimens were im- 

 mersed and became narcotized in one minute. No definite light 

 responses were observed. The animals were transferred to fresh 

 sea-water, but did not recover. Two similar specimens were im- 

 mersed in (1:4000) phenol. Definite "light" and "darkness" 

 responses were given within one or two minutes of immersion. 



