1869.] and Membranipora JBengalensis. 45 



generally amounts to three or four inches, probably sometimes 

 more. I have seen them ejected on every part of the column, 

 even at the base, when the animal is forcibly removed from its 

 place of attachment, in which case the large number of the acontia 

 forms a regular net work round the animal. It is, I believe, 

 principally due to the bearded ecthoraea of the cnidce, that the acontia 

 stick firmly to every thing which they meet, until the hooks are 

 forcibly removed, or until the organs themselves relax. For small 

 animals the acontia are, therefore, formidable weapons, and there can 

 be little doubt that the fluid of the cnidce acts as a kind of poison, in 

 the same way as it does in the Acalephce. 



The different modes of emitting the acontia from the body will 

 be mentioned subsequently, but I must make here some observa- 

 tions regarding their internal attachment, although it is very 

 difficult to pronounce a conclusive opinion on this point. I have 

 dissected several specimens for the sole purpose of obtaining a clear 

 idea as to the places where the acontia originate,* and it always 

 appeared to me that some of them are attached at the larynx, between 

 the ovavia and the craspeda, but at the same time there seem to be 

 some of them fixed below, near the centre of the base, between the 

 muscular thickenings of the mesenterial folds. I am not aware 

 whether any thing about the attachment of the acontia has been 

 previously observed, and it is possible that the basal attachment is 

 only auxiliary to the one at the larynx, so as to support the mus- 

 cular power required for their emission. 



m. Each ovarium consists of two parts, one placed on either side of 

 the primary septa. The ovaria are long undulating strings, which are 

 firmly attached with one end on the internal side of the larynx, then 

 partially all along the internal cavity between the mesenterial folds, 

 and loosely by some threads to the base. The halves of each pair are 

 perfectly symmetrical, they run in a slight curve, generally parallel to 

 the convexity of the column. The colour is a bluish^ purple, slightly 

 varying in tint in different specimens. 



* This operation is indeed not so simple, as it would appear, judging from the 

 transparency of the animal. As soon as a portion of the Sagartia is cut o&, it 

 immediately contracts to such a degree that it is almost impossible to observe 

 sepuiately any of the internal parts. 



