472 CHAPTEli. XXXVl. 



905. Zoantharia with Calcareous Skeletons are difficalt fco 

 deal with on account of the great contractility of the polyps. 

 Sublimate solution, which ought very often to be taken 

 boiling, sometimes gives good results. 



See also Lo Bianco, loc. cit., -p. 416. 



Sections. — See §§ 177 and 178, for undecalcified specimens. 



906. The Alcyonaria have also exti-emely contractile polyps. 

 In a former edition I suggested for their fixation either hot 

 sublimate solution or glacial acetic acid (§ 84). S. Lo Bianco 

 has since recommended essentially similar processes. GtAKBIni 

 {Manuale, p. 151) drenches them with ether, and brings into 

 strong alcohol. 



Wilson {Mitth. Zuol. Stat. Neapel, 1884, p. 3) kills Alcyo- 

 naria with a mixture of one part of strong acetic acid and 

 two parts of concentrated solution of corrosive sublimate, the 

 animals being removed as soon as dead and hardened for two 

 or three hours in concentrated sublimate solution. 



907. Zoantharia and Alcyonaria. — Bkaun {Zool. Anz., 1886,p. 

 458) inundates Alcyonium palmatum, Sympodium coralloides, 

 G-orgonia verrucosa, Cao-ynphyllia cyathus, and Palythoa 

 axinellae. with a mixture of 20 to 25 c.c. of concentrated 

 solution of sublimate in sea water with four to five drops of 

 1 per cent, osmic acid, and after five minutes passes into 

 successive alcohols. 



(This method also gives good results with Hydra andi some 

 Bryozoa and Rotifers.) 



See also § 14. 



BujOE (Arch. Zool. cajwr., ix, 1901, p. 50) kills VeretiUuvi 

 in sea water containing 10 per cent, each of formol and ether, 

 and after a minute passes into 2 per cent, solution of formol 

 in sea water. 



908. Hydroidea, Polypoid Forms. — For suitable narcotisation 

 methods see §§ 15 et seq. 



For killing by heat see § 13. 



Fixation. — In general the^polyps may be very well killed 

 in saturated sublimate solution, in which they should be 

 plunged for an instant merely, and bo brought into alcohol 



