REPORT ON THE ALCYONARIA. 121 



in the colonies dredged off the Manx coast, after being 

 kept in an aquarium for a few days, the polypes expanded 

 fully, and then presented the appearance shewn in PI. II, 

 figs. 1 and 2. Figure 1 represents the colony, about natural 

 size, and figure 2 one of the polypes enlarged. These shew 

 that the polype may expand to over three times its normal 

 height, the clear upper part of the body being about twice the 

 length of the opaque lower part. This expanded upper part 

 of the body is of a translucent white colour. The tentacles 

 are exceedingly slender and graceful, and may be extended to 

 a great length ; they are usually as long as the entire body 

 of the polype. They are very delicate, and have an entirely 

 different shape from that which they present when dead and 

 preserved in alcohol.* The stomodseum is usually dis- 

 tinctly visible in the expanded polype (see PI. II, fig. 2) 

 as a less translucent white band running from the mouth 

 downwards to the opaque red lower part of the body. 



The colonies which expanded in captivity were very 

 sluggish in their movements, and slow in responding to 

 stimulation. The specimens were dredged and placed in the 

 small aquarium on August 7th, and it was not until August 

 12th that the first polype of the first colony elongated its 

 body and expanded its tentacles. On the following day 

 (Aug. 13th), the whole colony of fifteen polypes was in a 

 completely expanded condition (see PI. II, fig. 1). But when 

 once expanded the polypes remained so, with very slight 

 movement of any kind, and it was not very easy to induce 

 them to retract the tentacles — agitation of the water sur- 

 rounding them, and even shaking of the stone to which they 

 were attached, seemed to have no efi'ect whatever. When the 

 tentacles were pricked with the point of a needle they slowly 

 retracted, and if the irritation was continued the upper part 

 of the body wall was slowly and gradually drawn inwards 



* Herdman, loc. cit., see pi. i, figs. 8, 9, 10. 



