168 FRANK E. BEDDARD. 



tlie nth ring, just in front of the first of the specially thickened 

 intersegmental septa. The second peculiarity concerns the 

 calciferous glands, or rather their equivalents ; for, like Mr. 

 Benham, I have been unable to find any calciferous glands 

 like those of Urochaeta. The oesophagus is a narrow tube 

 with greatly vascularised walls, there being apparently a con- 

 tinuous blood sinus below the lining epithelium. Its inner 

 wall is raised into numerous irregularly arranged folds ; in the 

 xiith segment it suddenly increases in diametei', and exhibits 

 a remarkable structure, which is illustrated in PI. XX, figs. 9^/., 

 lOca., 11. The folds which are distinctive of the oesophagus 

 become greatly increased in depth, and at the same time 

 regularly arranged ; each fold consists of two layers of epithe- 

 lium, enclosing in the space between them a blood channel. 

 The structure of this part of the gut, which occupies three 

 segments, is not unlike that of the calciferous glands in 

 Acanthodrilus (Beddard 3); its epithelium is not ciliated. 



§ Vascular System. 

 The vascular system of this worm is distinguished by the 

 enormous size of two pairs of " hearts/' which unite the dorsal 

 and ventral vessels in the xth and xith segments. Both in 

 dissection and longitudinal sections these vessels were seen to 

 be gorged with blood. The interior of each vessel was dis- 

 tended with a coagulated mass of blood, which, however, did 

 not consist of a uniform yellow-coloured clot ; but, as shown 

 in the accompanying figure (PI. XX, fig. 13), contained 

 scattered through the blood certain curious structures, con- 

 cerning the nature of which I feel rather doubtful. The two 

 pairs of hearts opened each by a relatively very narrow opening 

 into the two longitudinal trunks. The orifice of communica- 

 tion was in each case guarded by a well-marked valve, which 

 consists of a mass of elongated cells (see PI. XX, figs. 12, 13), 

 evidently a special growth of cells which line the blood-vessel 

 throughout. It is interesting to note the valve between the 

 heart and the dorsal vessel (fig. 13) projected into the former, 

 while in the case of the communication between the heart and 



