101 



cause the individual zocecia in the badly preserved colonies seem to me to show 

 a trace of an operculum, and if there is not an even transition in this regard 

 within the species we must very likely form a new genus for the species with 

 an operculum. The angular bending of the distal wall may reach its maximum 

 in B. dentata Lamx, where the two lateral halves in some zocecia almost reach 

 the proximal end (PI. V, figs. 1 a — b). 



Bugula caliculata n. sp. 



(PI. Ill, figs. 1 a-1 q.) 



The zocecia, which from the narrow, proximal end increase in width 

 distally, have on the outer distal angle a very short, curved spine, and on the 

 inner a very long thread-like spine a little lower in position. In very young and 

 developing colonies however the first 3—7 zocecia have 2—3 long spines, and in 

 such colonies the ancestrula is even provided with 6, of which the third (the 

 lowest) on each side is placed at double the distance from the second as the 

 latter from the first. The membranous portion of the frontal wall which in the 

 ancestrula occupies nearly half the length of the zocecium has in the common 

 zocecia a much larger extent. In the few single zocecia succeeding the ancestrula 

 there is found a constriction in the proximal part (figs. 1 d, 1 e). 



The avicularia occur only in a relatively small number, and are situated a 

 little within the outer lateral margin and a little distally to the proximal end of 

 the zocecium. Each zocecium of a pair, where the bifurcation commences, is in 

 most cases furnished with an avicularium, a rule, however with not a few excep- 

 tions, especially at the last bifurcations. Besides these, a number of avicularia 

 occur apparently without any very definite position. 



Ocecia small, globular, and their longitudinal axis is a continuation of that 

 of the zocecia. 



The stem is jointed and consists of a row of long, narrow segments (keno- 

 zooecia) widened a little at both ends and rounded quadrangular in section. The 

 distal end of such a kenozooecium is provided a little proximally to the joint 

 constriction (fig. 1 1), with a distal wall, saddle-shaped from side to side and 

 from the front to the base, which on each side is furnished with 4—5 small, 

 uniporous rosette-plates, all of which may sometimes be separate, sometimes con- 

 nected together in groups. This calcareous distal wall is continued internally 

 along each of the two lateral surfaces of the kenozooecium as a calcareous band 

 (fig. 1 q) which as time goes on increases in width and in thickness. The two 

 bands join together to a ring-shaped portion (figs. 1 1— 1 m) at the proximal part 

 of the segment, and the intention with the whole of this arrangement is evidently 



