20 Mr. T. Wliitelegge on Australian Poh/zoa. 



knobs of various sizes ; " zocecia immersed, directed towards 

 {what appears to be the base) the primary part of the zoarium. 

 Oral apertui'e rounded above, with a wide sinus below ; peri- 

 stomial orifice nearly round, margin slightly elevated, with a 

 subciicular pore on the upper border ; an avicularium on each 

 side of the mouth, frequently a third one in front ; mandible 

 triangular, generally pointing upwards. 



Loc. Holborn Island (20 fathoms). 



There are three specimens in the collection of the Austra- 

 lian Museum, one a flat piece j of an inch by -g- of an inch, 

 the other two have each three lobes ; the central one in the 

 larger specimen is fV from base to summit, and the lateral 

 lobes -g- of an inch in length, and nearly as wide ; all the 

 lobes taper a little outwards. The " semilunar slit " is not 

 seen in any of the specimens, but the peristomial opening is, 

 I believe, formed in the same manner as in the others ; 

 several of the zocecial openings are closed by a calcareous 

 plate, and have the appearance of young zooecia; the plate is 

 seen to be thinner at the margin; probably the slit-like 

 opening is not formed. 



Mr. Haswell's description of the mouth of this species 

 clearly shows that it was the anterior pore which he men- 

 tions as the sinus in the lower lip. He says ''mouth varying 

 in form, the lower lip sometimes straight, sometimes with a 

 small sinus, sometimes with a rounded central lobe." This 

 exactly describes the appearance of the anterior oral pore in 

 various stages of perfection. The peristomial orifice with the 

 pore broken down closely resembles the figure given on 

 pi. xlv. fig. 3, in Hincks's ' British Marine Polyzoa,' of 

 HcMzoforella hyalina ; and it was only after repeated exami- 

 nation that I saw the true oral aperture, owing to a belief 

 that the pore and the opening represented it. Although the 

 true aperture is not deeply immersed, it is difficult to see at 

 first on account of the peristome obstructing the view ; but 

 when once seen it presents a well-formed sinus in the lower 

 lip at the opposite end of the mouth to that of the pore. It is 

 from the apparent double character of the mouth that the 

 name Bipora is given to the genus. 



7. Bipora (?) elegans. 



Flabellopora elegans, d'Orb., Waters, Quart. Journ. Geol. Soc. Feb. 1887, 

 p. 71. 



Zoarium free, bilaminate, flabelliform in large examples, 

 ^ an inch wide by f of an inch deep, with a projecting 

 nodule in the centre on the concave side ; zooecia wholly 



