6 F. A. SMITT, 



culated structure of the stem. Now, what this character really denotes, in my former 

 papers at many instances I have shown on the Scandinavian bryozoa, and in the follo- 

 wing we shall see that same to be the case with several Floridan forms: the manner 

 of building the stem, with all the changes depending thereon, can only give characters 

 of a secondaiy value, while the form of the individuals alone, with their developmental 

 changes, will show the natural affinities. Thus the Nellia, as far as it yet is known, 

 comes nearest to the Cellularian type, and in a natural system must be regarded as 

 a Cellularian genus, modified, through its mode of growing, like the Cellariw. The 

 Farcimia, as that genus here is established, through its well defined apertural area, 

 which it closes, proximally, in the nearest agreement with some Membraniporidan forms, 

 for the same reason must be regarded as belonging to the Membraniporidan series. The 

 true Cellaria?, from which we must separate the Cellaria articulata (as being a Micro- 

 poridan form), through the younger form of their zocecia, place themselves in the 

 neighbourhood of the Flustrce. In the Flustrine type, however, the lower forms come 

 very near each other, though the highest differentiations of the type very much di- 

 verge. Thus, when the connecting links are missing, we can scarcely judge of the af- 

 finities and, probably, we must wait long, before we can trace the evolution of all 

 that digressions of the type, thus finding natural grounds for establishing families and 

 genera etc. Now, as I have shown in my former papers, the Escharine and Celleporine 

 types have developed themselves from various stages of Flustrine constitution, and the 

 progress of that development very often has left its traces in the present evolution of 

 the colonies, what is expressed in the variations of the form of the zocecia from the 

 beginning of the colony to its last stages. Therefore, for the natural arrangement, 

 after this principle, of the Escharine and Celleporine groups, it will be necessary to 

 know the development at least of the leading forms. As an instance, how far these 

 developmental relations are to search for, I will show the development of a Vincularia, 

 that I do not venture to identify with any formerly known species, wherefore I pro- 

 pose to give it the name 



Vincularia abyssicola (Pl. I, figs. 60 and 61). 



Pourtales has brought up two fragments of this species, the one fixed on a 

 Betepora from 450 fathoms off Cojima, Cuba, the other on a Nidlipora from 68 fathoms 

 at Florida. The one of these colonies, in its outer appearance, after the hitherto pre- 

 valent opinions, would be a Membraniporidan form (fig. 60), encrusting the Betepora. 

 The zocecia are purely flustrine, linguiform (pyriform) covered by a 3'ellow ectocyst, 

 into whose distal part the halfelliptical operculum is moving itself. From each of the 

 proximal corners of that aperture, a furrow is going back proximalby. The avicularia 

 retain the form and position of the zocecia, as buddings of the same order, with the 

 only difference, that the operculum is transformed to a mandible of triangulär form 

 Avith the tip produced, acute, and with the sides bordered to an elliptical form by a 

 membrane. Taking away the yellow, primary ectocyst, below this we find nearly whole 

 the front side, of the zocecia as well as of the avicularia, covered by a white, shining, 



