:]:]0 W. M, Bale: 



a^'iets peii'cctlv with the foregoing account of S. undidafa. It is to 

 1x5 noted that Jickeli describes the lining of the hypostome as- 

 endodernuil. 



In 1909^ 13ioch esta))lished the genus Bonntviella and the family 

 BoNNEViELLiDAio for the Camimnularia grandis of Alhnan, on. 

 chaiaeters wliicli, lie claimed, distinguish it sharply from all other 

 Camjjanularians. These characters, however, are mainly those 

 which Jickeli had already shown to exist in C. caliculata, with this, 

 exception, that the distal cavity which is enclosed above by the 

 prolx)scis or corona (which he calls the veloid), is lined by ectoderm, 

 instead of endoderm, and is regarded by him as a pre-oral cavity^ 

 not as a hypostome. He says: — "The greatest difference from all 

 other hydroids is found in the mouth-part of the hydranths. Right 

 on the place of union of the tentacles, and on their inner side, i» 

 founil a velum-like lamella, the ** veloid." This veloid is extended 

 like a disc over the whole mouth-part of the hydranths, and has. 

 only a small centrally situated hole through which admission is. 

 obtained to a pre-oral cavity. The veloid is composed of two" 

 ectodermal cell-layers, which are divided by a membrane, this 

 mem.brane apparently springs directly from the stiitz-membrane 

 of the tentacles, and must be considered as a continuation of the 

 s^ne. Inside the veloid the ectoderm is continued as a siingle- 

 layered cylinder-epithelium wiiich, liowever, passes over into a 

 cylinder-epithelium of several layers towards the bases of the 

 tentacles. The transition fronl ectoderm to endoderm is found at 

 the under side of the tentacle-bases, so that an ectodermal food- 

 passage seems to be formed ; whether, however, this is caused by the 

 coiitiaction of the hydranth I do not venture to decide with 

 certainty. 



Fani. BONNKVIKLLIDAK. 



** Thecate Hydroida provided with a veloid, so that a pre-oral 

 cavity is constituted. The single known genus 



BONNKVIKLLA, UOV. gen. 



*' Trophosome. Hydranth with a single series of tentacles which 

 are united together as far as the veloid. Ectoderm-lined food- 

 passage. (?) Hydrothecae bell-shaped, with thin diaphragm. Erect 

 colonies which spring from a rhizocaulon. 



"Gonosome. Gonangia dispersed over the stem. Gonophores 

 sessile. Colonies sexually distinct." 



1 N\ t MayazJH f. Naturvidinsk, B. 47, 19 9, p. 195, fig. I. 



