94 



in the degree of its development with B . 6 in fig. 4. The proboscis has acquired its pigment- 

 Hne, while the two arms of the first pair are short bodies, each ending in a knob containing 

 refringent vesicles. The collar is marked off dorsally from the metasome by a slight groove. 

 It may be noted that the male individuals of C. sibogae remain at this stage of development 

 in respect of their arms and of the absence of any demarcation between body and stalk. 



F'ig. 30 is an anterior view of an older bud, more highly magnified. The proboscis is 

 somewhat torn on the right side of the figure, and the first arm of the same side has been 

 lost. The other first arm is a good deal longer than in fig. 8, and a second pair, also with 

 vesicles, has been developed behind it. The mouth and a small alimentary canal are seen through 

 the more or less transparent wall of the proboscis, while it may specially be noted that the lower 

 lip or operculum (('/.) is continuous with the second arms, which are for the moment those which 

 are most posteriorly situated. Ovaries are already present, but are not represented in the figure. 



Fig. 9 is a similar view of a somewhat older bud, in which some indication of the 

 development of new arms may be observecl. In fig. 32 four pairs of arms are present, five of 

 which shew young tentacles. Xo vesicles can be found at the tip of the first arm of the left 

 side, but a few are present in the corresponding right arm and in the second and third left 

 arms. Their condition in the second left arm seems to shew that they are in process of being 

 lost. This is probably a normal feature in this species, since it is practically certain that no 

 vesicles are present in any of the arms of some of the adult individuals, although I have been 

 able to recognise them at the tips of the first two pairs of arms in one or two adult zooids. 



Most of the adult organs are already developed in fig. 32. The intestinal limb of the 

 alimentary canal is seen in the foreground, while the mouth (;;/.) can be made out by deeper 

 focussing. On the right side of this is seen the triangular lateral lobe of the operculum [op.r.). 

 The two ovaries are visible, somewhat overlapped by the rectum. The body is still a direct 

 prolongation of the stalk, and it may specially be noted that the arms are developed in such 

 a position that their food-grooves at first face the posterior side of the proboscis. The posterior 

 limb of the vascular loop of the stalk is seen attached to the bend of the alimentary canal. 



Fig. 31 is a similar bud, seen obliquely from the left side. The alimentary canal has 

 acquired its adult arrangement, and the left gill-slit [g. s. e.) and collar-pore {c. c. e.) are shewn 

 in the fieure, which further indicates the course of the food-grooves of the first three left arms 

 on their way towards the mouth. 



The bud B. 4 in fig. 4 possesses the full number (5) of arms on the right side, the 

 fifth arm having the form of a nearly spherical swelling which is partly concealed by the base 

 of the fourth arm. This specimen, like fig. 32, shews clearly that the arms are dorsal outgrowths 

 of the collar-region. 



Fig. 29 illustrates the fact that the stalk-vessels are well developed in the bud, a fact 

 which is no doubt of great physiological importance in connexion with the supply of nutriment. 

 The posterior limb of the vascular loop is, as usual, attached to the bend of the alimentary 

 canal, while the anterior limb fades away in the anterior part of the body-wall of the metasome. 

 Fig. 28 shews the two parts of the stalk-vessel of the same bud at a point a good deal nearer 

 the base of the stalk. 



