MEDITEREANEAN AND NEW-ZEALAND EETEPOEiE. 265 



wliicli are common in the Reteporce. All my specimens were 

 dead, and no chitinous appendages were found. 



This Betepora is common in the material brought up from 

 about 225 fathoms by the coral-fishers near Capri, but I have not 

 seen it from Naples or Eapallo. It does not show any reticula- 

 tion, so that if Busk's genus Reteporella were recognized it would 

 have to be placed in it ; but the advisability of dropping the genus 

 Reteporella is clearly indicated by this species, and is quite borne 

 out by the three species so classed by Ortmann *, as in zocecial 

 characters they very closely resemble known species. 



Probably this is the species which Risso described "with 

 " rameaux cylindriques nullement entrelaces,'''' and named Retepora 

 Solanderia ; but as the characters to which we should now give 

 most attention are omitted, this is not clear. 



Retepora arhorea, Jullien, is described as finely reticulated on 

 both the anterior and dorsal surface, but in all other respects the 

 ' Travailleur ' and Mediterranean specimens agree. The name 

 arlorea was previously employed by Eisso, and therefore cannot 

 now be used, although we cannot be sure what Eisso had before 

 him ; perhaps it was Reticulipora dorsalis, Waters. 



The zocecial characters are in many respects the same as those 

 of R. Imperati, Busk ; but, as mentioned in my Supplementary 

 ' Challenger ' Report, I have not seen any reticulating R. Imperati 

 from the Mediterranean, but perhaps in some cases there may 

 be foliaceous or reticulate growth according to the conditions 

 of the locality. The R. Imperati, Busk, of the ' Challenger ' from 

 Porto Praya, usually has the avicularia to the central zooecia, 

 and has large avicularia on the dorsal surface. 



A group may be made round tessellata including R. elongata 

 (= R. tenella, Ortmann), R. Imperati, Busk (= R. tumescens, 

 Ortmann), R. Solanderia, Eisso, which, so far as known, have a 

 very characteristic operculum f. In this group the ovicell is 

 widely open, more or less cucullate, and a considerable distance 

 from the opercular aperture ; in R. tessellata (PL YI. fig. 6), R. 

 Imperati (PI. VI. fig. 5), and R. Solanderia the opening extends 

 far up with parallel sides, so that it has somewhat the form of 

 a wide fissure, and we may see how from this, or vice versa, the 



* Ortmann, A., " Die Japanische Bryozoenfauna," Arch, fiir Naturgesch. 

 vol. i. 1890, p. 36. 



t The operculum of B. tessellata, var. ccespitosa, Busk, is drawn reversed in 

 three cases in the ' Challenger ' Eeport. 



