102 SIDNEY F. HARMBH. 



and is not concealed either by the zooecia or by other parts of 

 the ooeciostome. The specimens on which my account of this 

 species is based were found principally at Godosund, a small 

 island off the north of Tysnaso, at the entrance to the Bjorne 

 Fjord in Norway. They were not uncommon on the fronds of 

 Laminaria saccharina, where they occurred in company 

 with Lichen opora verrucaria, Fabr. Most of the speci- 

 mens collected at the end of June had fully developed ovicells. 

 Specimens collected at Lervik, in the Hardanger Fjord, at the 

 same period in a previous year were, however, not provided 

 with ovicells. Smitt describes the species as occurring on 

 Laminarise and other Algse from the Gullmar Fjord (in the 

 south of Sweden) to Spitzbergen, so that the species may fairly 

 be regarded as a Northern one. 



I think there can be no doubt of the specific distinctness of 

 this very beautiful form, which is more easily recognised, at all 

 stages of its growth, than are most of the European species of 

 Tubulipora. It differs strikingly from the other species here 

 described in having its zooecia isolated, or only associated two 

 or three together. The connate arrangement found in other 

 forms is usually completely absent; and even in the fertile 

 lobes the zooecia stand up for the most part singly from the 

 roof of the ovicell, the lobes of which may thus unite distally 

 to the zooeciura. Even in these cases the suture or septum 

 between the two ovicell-lobes is easily seen near the growing 

 edge, and I have no reason to suppose that contiguous lobes 

 really fuse at any time. 



The zooecia are more clearly marked off from one another in 

 the basal part of the colony than is the case in most species, 

 the proximal part of a zooecium being very convex as far as the 

 suture where it joins another zooecium. In other species 

 parts of the zooecia may form more or less extensive flat surfaces, 

 as is well seen in the connate series or in the basal adherent 

 parts of the colony. The ectocyst of T. aperta has a delicate 

 appearance, and there are noticeably fewer pores on the zooecia 

 than in most other species. Numerous concentric lines of 

 growth, passing transversely across the zooecia, are clearly 



