28 Cyathocormus mirabilis n. g., □. sp. 



genus Colella, the buds seem to be produced near the base of the 

 colony and gradually pushed to the outer surface of the head. 

 Here, probably, they soon reach maturity, the female individuals 

 producing also a tailed larva from an egg fertilized by the sper- 

 matozoa of the older zooids. They are then constantly pushed 

 upwards, and finally, having lived through the entire length of 

 the head, they reach the free margin as old zooids, die and drop 

 off. This is, I believe, the reason why we do not find young 

 buds or functionally active reproductive organs in the zooids 

 situated in the distal part of the head. 



The similarity in the arrangement of zooids within the colony 

 in Cyathocormus and in some members of the genus Colella 

 (j=Sycozoa)^ such as C. pidclira, C. temiicaulis^ etc. is also very 

 striking. The zooids form, in both cases, longitudinal rows 

 grouped in pairs, in which they are placed alternately in such a 

 manner that the endostyles are turned towards one another. 

 Moreover, in the last species the head is sometimes truncated at 

 the top and much resembles that of Cyathocormus, so that if the 

 head became hollow inside the colony would have exactly the 

 same form as that of our species. 



Turning now to the anatomy of the individual zooids we 

 again find that the present genus is closely related to Coklla among 

 the Distomidae and to Diplosoma. In all these forms the body is 

 divided into thorax and abdomen, to which a vascular appendage 

 is attached. The branchial sac has four rows of stigmata. The 

 intestine forms a simple loop lying posteriorly to the branchial 

 sac. The stomach is smooth walled. In the possession of a 

 large incubatory pouch, however, Cyathocormus agrees with Colella 

 and differs from Diplosoma. If, in addition, the colonies of 

 Cyathocormus should turn out to be really dioeceous, which 

 is very probable, the relationship between the two genera 

 would become decidedly closer.^ In the unlobed condition of 

 the branchial aperture, on the other hand, Cyathocormus differs 



1. According to the researches of Caullert ('95) members of the genus Colella {^Sycozoa), 

 with the single exception of C. thompsoni, are all dioeceous. 



2. Axtrallium ^spongiforme Giard (72) has unlobed branchial aperture. 



