General History of the Marine Polyzoa. 173 



systematic value of this character. But I confess it seems to 

 me unlikely that it has the kind of importance which Dr. 

 Jullien assio;ns to it. 



Additional Locality. Cape of Good Hope, common (M". 

 Maurice Ghaper). 



Ibid. (p. 38 Sep.). 



Memhranipora permunita, sp. n. 



This species is ranked as a variety of Cellepora Michau- 

 diana, d'Orb., by Waters *. Miss Jelly, in her ' Catalogue,' 

 reverses this decision on the ground of the important ditfer- 

 ence in the avicularia, and places the latter amongst the 

 synonyms of the present form. The distinction, however, 

 between the avicularia, tliough sufficiently striking (they 

 belong to different classes), is by no means the only ground for 

 separating the two forms. The zooecia are also described, not 

 merely in slight particulars, but in general character. It is 

 sufficient to instance the marked difference between the aper- 

 tures of the two species both in form and in the proportion 

 which they bear to the rest of the area. M. perniunita is 

 clearly not a mere variety of M. Micliandiana^ but a distinct 

 species ; and the latter has therefore no claim to a place in 

 the synonymy. 



Ibid. (p. 39 Sep.). 

 Memhranipora [Caleschara) denticulata, MacGillivray. 



The account which I have given of the structure of the 

 cell in this species is, I believe, strictly correct ; but I cer- 

 tainly do not adhere to my interpretation of it. Caleschara 

 belongs to the family Steganoporellida? f (which had not been 

 properly defined when my paper was written), and would find 

 a place in the genus OnycJiocella, Jullien, but for the entire 



* " On Clieilostomatous Biyozoa from Aldiuga &c., South Australia," 

 Quart. Journ. Geol. Soc, Auf^-ust 1885, p. 289. 



t In the defiiiitiou which I have given of tliis family (" Critical 

 Notes," ' Annals,' Feb. 1887, p. 162) the membranous front wall is 

 described as " carrying the orifice and operculum.'' But this is not uni- 

 versally true of the forms embraced in it. It is the case in Onychocella, 

 Jullien, and kindred forms, but not in Stecfanoporella and Thalamoporella. 

 This character must therefore be removed from the family diagnosis. 

 Probably this difference is sufficiently important to warrant a division of 

 the family. Jullien's group Onychocellidae has been formed for species 

 in which the membranous ectocyst carries the orifice. In these forms 

 the true front wall is in all respects similar to that of the Membraniporte, 

 and the oi'ificeaud operculum are of the primitive Membraniporidan type. 



