or Little Known, Polyzoa. 133 



forming a slightly hollowed sinus or nearly straight. A 

 broadly elliptical avicularium placed obliquely on each side 

 of the mouth. 



Port Phillip Heads. 



The structure of the mouth approximates to that of 

 Gemellipora stviatida. 



Smitticc cribraria, n. sp. Plate I., fig. 7. 



Zoarium encrusting. Zocecia large, separated at the grow- 

 ing edge by raised lines ; towards the older parts distinct, 

 but the separating line not raised ; whole surface occupied 

 by large, closely set foramina, largest at the circumference ; 

 a hammer-shaped denticle in the oral sinus. Ocecia 

 rounded, smooth or pitted, sub-immersed. 



Port Phillip Heads. 



On one or two of the zooecia there is what seems to be 

 an avicularium with an enormous flat, rounded mandible 

 similar to that described by Hincks on Lepralia bifrons. 



Family Adeonid^e. 



In the Challenger Polyzoa Mr. Busk proposes a new genus 

 Adeonella, which with Adeona (including Dictyopora) he 

 places in a family Adeoneaa. Under Adeonella he places a 

 number of species previously und escribed or referred to the 

 old incongruous genus Eschar a. These, as mentioned by him, 

 differ from Adeona chiefly in the absence of a flexible stem, 

 agreeing in the presence of distinct avicularian cells, ocecial 

 cells and in the curious articular processes of the avicularian 

 mandibles, as well as in the presence of a suboral pore or 

 cluster of pores. These pores, however, as recently pointed 

 out by Mr. Waters (Quart. Journ. Geol. Soc, Aug., 1885), 

 differ essentially in several of the species. In one group, to 

 which he would restrict the generic name, represented here 

 by A. ylatcdea (Busk) and A. dispar (M'G.), the pore is 

 formed by the growth of the peristome, and in reality opens 

 into its tube external to the operculum and true mouth, 

 while in the other group the pore or pores open into the 

 body-cavity below the mouth. These last, with Adeona and 

 Dictyopora, in which the structure is similar, he refers to 

 Micropovella. I cannot agree with this view, and it seems 

 to me that Busk is quite right in forming a separate family. 

 The characters chiefly are that in the Adeonidse, in addition 

 to the ordinary zocecia, there are other purely avicularian 



