i8 N. Annandai^e : The Fauna of Brackish Ponds. [Vol, II, 



Gonads — 



The gonads arise as a pair of small reniform bodies ^ one Ijdng 

 on each side of the stomach. They branch as they develop, 

 however, and become at first lobate, then dendritic, and finally 

 form a broad zone, interrupted in front and behind, round the 

 calyx, the branches being closely pressed together. All the colonies 

 I have examined have been either male or female as colonies, but 

 there were some indications in the female ones of protandry having 

 occurred. I have not seen fully ripe ovaries or embryos, and am 

 uncertain whether a brood-pouch exists. 



Nervous System — 



A relatively large ganglion exists near the centre of the calyx, 

 in the bend of the alimentar}" canal, and sends oft" radiating nerves. 

 Its position is the same as that occupied b}" the ganglion of Pedicel- 

 Una. 



Mtisciilaturc — • " 



I have been unable to detect muscles in the calyx, unless 

 the structure joining the stomach to the base of the calyx is of 

 this nature. The greater part of the stalk consists of vertical, 

 nucleated muscle-fibres. 



Stalk — " 



The stalk is covered by a smooth, minutely annulated cuticle, 

 not very thin but quite transparent and colourless. Within the 

 cuticle, for a short distance below the calyx, there is a single layer of 

 flattened cells with nuclei that stain deeply ; but this layer only 

 extends for a short distance. The diaphragm is tangential to the 

 main axis of the stalk. The remainder of the stalk apparently con- 

 sists of a uniform mass of muscle-fibres. Whether flame-cells occur 

 in this mass I am unable to say, not having cut sections. The calyx 

 apparently dies at not very infrequent intervals and falls off, leav- 

 ing a pointed tip to the stalk. A new calyx is then formed within 

 the distal part of the stalk, apparently from that part of it which 

 possesses a la3^er of flattened cells immediately within the cuticle. 



Movements — 



The movements of the polypide are slow, except in the case 

 of the tentacles and sphincter muscle, which are folded in and 

 contracted with great rapidity. The tentacles, when extruded, 

 are usually held with their tips bent inwards towards the centre 

 of the circle outlined by the lophophore, but they can be straight- 

 ened out so as to lie parallel to the main axis of the polypide, and 

 their tips can be applied together when they are fully extended, 

 in order that food, consisting of various minute organisms, may 

 be seized between them. I am indebted to my friend, Mr. F. M. 

 Howlctt, for the sketches reproduced in figure 7 and representing 

 living ])oly]oides in various attitudes. ■ - ■• , 



