H3 



Zoarium rather more robust than that of E. dcticatitla. and the zooecia slightly larger; 

 their immersed portions sometimes very long. Ovicell not bifurcating with a branch ; its roof 

 pierced by isolated peristomes, and its ooeciostome not terminal. 



The present species is slightly coarser than E. delicatula, and its zooecia are somewhat 

 larger. In some of the specimens referred to it, the zooecia have a very long portion immersed 

 in the general substance of the branch, before they give off their free peristomes J ) The feature 

 which specially distinguishes this form is the ovicell, which has the character shown in fig. 14. 

 In this specimen the ovicell is rather broad, with a gently convex frontal surface, which descends 

 very steeply into the lateral walls of the branch. It is "simple" in character, not bifurcating 

 with the branch. In the fact that its roof is traversed by zooecial peristomes (usually isolated) 

 it differs from the other 'Siboga' specimens. The ooeciostome (if this structure has been correctly 

 identified) is situated at a long distance from the distal end of the ovicell, instead of being 

 terminal, as in the other two species. In fig. 14 it seems to be the opening which is adnate 

 to an ordinary peristome, not far from the proximal end of the ovicell; and it is not unlike 

 an ordinary orifice in shape. Ovicells of a similar type are present in 202. D., in which the 

 ooeciostomes also have the character shown in the figured branch. One of the Torres Straits 

 specimens (90) has ovicells in which the roof is traversed by zooecia, although the ooeciostomes 

 cannot be seen with certainty. The remaining specimens in the above list have no ovicells; 

 and the determinations must be regarded as doubtful. 



All the specimens described are small fragments. 

 Measureraents, in rj. (fig. 14): 



YVidth of branch, at lower end, 580 ; 



Length of inflated part of ovicell, 1,820; 



Greatest width of inflated part of ovicell, 1,000 ; 



Diameter of peristomes, 130 — 150; 



Diameter of orifices, 100. 



Mr Waters (1. cit.) has stated that in E. intricaria the zooecia pass through the ovicell. 

 This is the principal justification for the determination of the 'Siboga' specimens, which are, 

 however, more delicate than those described by Busk and may belong to a distinct species. 

 Their fragmentary condition does not permit any statement to be made as to the character of 

 the zoarium; which, according to Busk's original description, should form "dense intricate masses 

 of considerable size". 



Fam. Diastoporidae Busk. 



Diastoporidae Busk, 1S59, "Monogr. Foss. Pol. Crag'", Palaeont. Soa, pp. 91, 113. 

 Diastoporidae Smitt, 1866, "Krit. fort. Skand. Hafs-Bry.", II, Öfv. K. Vet.-Ak. Förh. XXIII, 

 P- 395- 



I use the Family Diastoporidae in the sense in which it was understood by Busk and 



1) The greatly elongated zooecia seen in some of the specimens (fig. 13) have not been found in fertile branches: and it is 

 possible, though not very probable, that they may not belong to the same species as the fertile branches. 



SIEOGA-EXPEDITIE XXVIII17. 



