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In the main stem the two branches are both given off on the side towards which the 

 angle of the stem is dirccted. The third branch, which gives rise to rootlets, may come off 

 opposite the two ordinary branches (and therefore from the re-entrant angle of the stem), or 

 quite asymmetrically. At the division of the branches the main stem is suppressed at each node, 

 so that the two branches of the new order are alone left. A branch may bifurcate successively 

 3 — 5 times. The main stem is traversed by a diaphragm, possessing a central perforation, 

 immediately beyond the node; and a joint is formed in this position by a diminution of the 

 thickness of the cuticle (fig. i). A similar development of a diaphragm and of a joint is seen 

 at the origin of each branch ; and the rootlets are also provided with a diaphragm at their 

 points of bifurcation. The main stem usually has no zooecia, though a few may occur; but the 

 presence of scars, sometimes in the form of small papillae (fig. i), indicates that zooecia have 

 been borne, in those positions, at an earlier period in the life of the colony. 



The branches, on the contrary, are provided on one of their aspects with a doublé 

 series of zooecia, sometimes represented merely by scars (fig. i), which have a definite alternate 

 arrangement. A single internode usually bears from 3 to 5 pairs of zooecia, although the 

 number of zooecia is sometimes odd. 



The zooecia are constricted at their base, as in other species of the genus, and are 

 thus readily deciduous. I have not found any evidence that a new zooecium can be developed 

 from an old scar : ). 



In form the zooecia are sub-cylindrical, the broadest point being in their proximal half 

 (figs 2, 4). They agree precisely with those shown by Busk in his fig. 1 b (PI. VIII) except that 

 they become quadrangular towards the orifice; which, in the retracted condition, is quite square. 

 This condition is not alluded to in Busk's description. The tentacles are 8 in number. The 

 pharynx is rather large and is succeeded by a narrow, elongated oesophagus, which (in the 

 retracted state) passes distally and then opens into a distinct gizzard, stated by Busk to be 

 absent. The stomach and its caecum are large. Parietal muscles are present in several groups, 

 usually of two fibres each. 



The following measurements, in ij., of the several parts of the colony agree closely with 

 those recorded by Busk : 



Length of an internode of the main stem, 1900; diameter, 250. 

 Length of an internode of a branch, . . . 1100; diameter, 100 — 180. 

 Length of a zooecium, 480 ; greatest diameter, 150. 



A specimen from Japan, in the Collection of the University Museum of Zoology at 

 Cambridge -), is certainly referable to the present genus, but it appears to belong to a distinct 

 species, so far as can be ascertained from the mounted slide, which is not a very successful 

 preparation. The zooecia are distant from one another, the interspaces being nearly equal to two 



1) LEVINSEN ("Régén. totale des Biy.", Buil. Acad. Roy. Sci. Danemark, Ann. 1907, N u 4, p. 152) has observed this regeneration 

 in Valkeria and Bowerbankia. 



2) Off Tokyo, 53 fathoms, A. Owston Goll., Reg. June 23, 1902. 



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