384 



Dr. C. A. MacMunn. 



end of the spectrum was absorbed, probably from the presence of 

 tetronerythrin. 



The greenish-white cceca of another specimen gave the alcohol a 

 yellow colour, which showed a band from X678 — 651 (which reading- 

 approaches nearer to that of the enterochlorophyll of Mollusca and 

 Crustacea.) When an alcoholic solution of green coeca was evaporated 

 on the water bath, a sap-green residue was left, which was only 

 partially soluble in chloroform, a dirty green-brown residue being 

 left still undissolved. The chloroform solution gave four bands : — 



1st Band X678— 637 



2nd „ ..... . .... A614— 596 



3rd „ ........ .. X546-5— 530 



4th „ X514— 494 



Nascent hydrogen, generated by the action of tin and hydrochloric 

 acid, and magnesium and aeetic acid, failed to change this colouring- 

 matter, the spectrum produced being 'the same as that got by the 

 action of nitric acid on alcoholic solutions.* 



Asterias aurantiaca. — The brownish cceca when extracted with 

 alcohol yielded an orange-coloured solution. which gave the following 

 bands : — 



1st Band,. X668— 653 '5 



2nd „ ., X612— 596 



3rd „ A515— 534? 



On adding nitric acid the usual five-banded spectrum of acid 

 enterochlorophyll appeared. The orange colour of this solution was 

 no doubt due to the presence of tetronerythrin, to which the integu- 

 ment seems to owe its colour. 



Echinus esculentus.f — The brown colouring-matter adhering to the 

 outside of the intestine and madreporic canal yielded its colouring- 

 matter to alcohol, which became a yellow colour. This showed the 

 band in red and also that before D, and a third feeble one before E. 

 In a specimen of Echinus which had greenish-white spines, the peri- 

 visceral cavity contained a large quantity of a 'brownish mass whicli 

 when dissolved in alcohol formed a brownish-yellow solution, which 

 presented a well-marked enterochlorophyll spectrum with the following 

 measurements : — 



1st Band :\670— 653*5 



2nd „ X612— 596 



3rd „ X545— 534 



4th „ X496— 473? 



* And oxidising agents gave a similar negative result. 

 _ f I am not certain whether the urchin was Echinus esculentus or not. The first 

 specimen mentioned above had white spines, the second whitish-green spines j they 

 both belong to the same species, and are commonly known a» " Sea-box.es." 



