87 



In tig-. Sy, the aliniciitary canal is representecl by an excessively small structurc, in which 

 a lumcn can barely be detected. As this immediately precedes the appearance of the recurreni 

 or rectal limb of the canal, it api)cars to correspond with the stomach or tlie second stomach 

 of the female. The vestioial character of the alimentarv canal is thus distinctlv indicated, and 

 it can hardly be rush to assert that no digestion takes place in the male zooid. 'Ihc dorsal 

 vessel has reached its maximum size in this section, and the vessels to the testis are distinct. 

 The ventral mesentery is probably complete on the side of the alimentary canal oppositc the 

 dorsal vessel. 



Two sections later (fig. 88) the recurrent limb of the alimentary canal is seen as a 

 cylindrical body with an obvious lumen. This meets the body-wall at one point, which probably 

 represents the anus, although I have not observed any indication of an actual perforation. The 

 rectal limb of the alimentary canal was obviously lying in a nearly frontal plane ; and it will 

 be noticed that in the individual shewn in figs. 95, 96, the rectum travels but a short distance 

 in the direction of the anterior end of the animal. The dorsal vessel in fig. 88 is continued as 

 a lobe which lies to the left of the rectum, the right testicular vessel being also visible. In the 

 next section the dorsal vessel has completely disappeared, without apparently giving off any 

 branch in this direction. 



The proximal part of the male is of fairly uniform structure (fig. 89). The body-cavity 

 remains spacious, and there are distinct indications of a median mesentery. At the two extremities 

 of this mesentery are an anterior and a posterior vessel {a.z'.,p.z'.) which, in the particular male 

 figured were more distinct near the stalk than nearer the other end of the metasome. The 

 anterior side of the body-wall has a layer of longltudinal muscles {iiis.) which correspond with 

 those of an ordinary female Cephalodiscus. 



There can be no reasonable doubt that the two vessels shewn in fig. 89 are continued 

 into the two stalk-vessels which I believe to be typical of Cephalodiscus. It will be noticed that 

 the relations of these vessels in the greater part of the testicular region of the animal is like 

 those of the vessels in the stalk of an ordinary zooid; that is to say, each vessel is closely 

 apposed to the inner side of the body-wall. The anterior vessel is indeed found in this position 

 in the body of the female zooid, but it will be remembered that the posterior vessel, on entering 

 the body, in the female, becomes attached to the second stomach (fig. 22). Taking these facts 

 into account, and considering further the po.sition of the bend of the alimentary canal, it appears 

 that the greater part of the "body" of the male is really a dilated part of the stalk; or in 

 other words that the testes have grown far beyond the limits of the body, as that term is 

 understood in the female, and have extended into the cavity of the stalk. 



This fact may have some hearing on the remarkable statements made by Conté and 

 Vanev (02, I, p. 64) with regard to the testis of Rhabdopleura. That organ was described by 

 L.'\NKESTER (84, p. 633, PI. XL, fig. 7) as an asymmetrical body, situated on the right side, 

 and opening near the anus. It has in fact much the same position as one of the gonads of a 

 female Cephalodisais, except that in some cases it appears to form a hernia-like projection of 

 the body-wall in which its blind end lies. Lankester points out that the young testis is po.ssibly 

 represented by the "cellular body" described by Sars (72, p. 5, PI. II, fig. 15, r) in the same animal. 



