274 



Genera: 



The aperture surrounded by spines, with a concave poster and 

 with no sinus; an avicularium proximally to the aperture; distal wall 



with uniporous rosette-plates; ooecia present Savignyella n. g. 



Catenaria d'Orbigny. 

 (S. Lafonti Audouin^.) 

 The projecting aperture not surrounded by spines, but with a 

 rounded sinus; distal wall with multiporous rosette-plates; avicularium 



and ooecium wanting Halysisis Norman ^. 



(//. diaphana Busk^.) 



Time has not allowed of my entering into a close examination of the two 

 species, which I think show sufficiently great conformity to belong to the new 

 family that I have been obliged to found for them. It is possible that ^Catenaria' 

 attenuata Busk^ may also be entered in this family. With regard to the question 

 of their descent, they seem to me to show relationship particularly to Bicellariidae, 

 and of characters that favour this opinion I may mention the slight calcification, 

 the long slender form of tlie zooecia, the form of colony and the structure of the 

 ooecia. Also the freely projecting avicularium in S. Lafonti may be taken as evi- 

 dence of such a relationship. While I have found a covering membrane on the 

 frontal surface in C. diaphana, I have not succeeded in finding one in S. Lafonti, 

 in which however according to the examination made by Calvet it must be 

 supposed to be present. — The two just-mentioned species have by Busli* and 

 later authors been called Alysidium Lafonti Aud. and Catenaria diaphana Busk. 

 But it has been necessary to make two aew generic names, as the name Alysi- 

 dium must be kept for A. parasiticum Busk, and Catenaria Contei Aud. is the type 

 of a genus belonging to the family Catenariidae (see pag. 213, note). 



Family Hippothoidae. 



Diazeuxidae JuUien. 



The zooecia, which have no covering membrane, are generally thin-walled, 

 glistening, more or less distinctly longitudinally or transversely striated, and the 

 calcification, which constantly increases simultaneously with the growth, takes 

 place in transverse belts, of which a greater or smaller number often terminate 

 in thin protruding margins, which surround the frontal surface like a belt. 



" 98, pi. 13, figs. 2,1—2,7. 2 84 a, p. 295. » 8, p. 14. ■* 2, pp. 13—14. 



