Description of Neiv or Little Knoivii Polyzoa. 109 



in the lower lip. In older zooecia, the peristome becomes 

 raised, and very large porcellanons nodules become developed. 

 Between the zooecial nodules are numerous large pores. Tiie 

 Goecia are immersed, flattened in front, with two or three 

 large white-bordered pores ; the border thickened, and with 

 several large nodules. The suboral avicularium, which is 

 present in the large majority of zooecia, is also a marked 

 feature. The space below the mouth, containing the avicu- 

 larium, is usually destitute of nodules. The size and 

 prominence of the nodules make the oval aperture seem 

 very deep, and give the specimen a very peculiar appearance. 

 Western Port, Rev. Mr. Porter. 



SCHIZOPOEELLA PORTERI, n. sp., PI. Y, Fig. 6. 



Zooecia confused, indistinct ; surface smooth and polished ; 

 oral aperture rounded above, with a well detiued wide sinus 

 in the straight lower lip. Below the sinus, a small avicu- 

 larium with vertical rounded mandible, on the upper edge 

 of an elevation of the cell. Numerous scattered avicularia 

 between the zocecia, with triangular mandiljles, on mound- 

 like elevations. Ooecia subimmersed, a nearly circular 

 portion in front remaining membranous. 



The scattered avicularia, and confused arrangement and 

 size of the zooecia, give a superficial resemblance to some 

 specimems of Rhyncliopora hispinosa, from which, however, 

 the structure of tlie mouth is quite difterent. The incom- 

 plete calcification of the ooecia is very peculiar, and seems to 

 be constant. 



Western Port, Rev. Mr. Porter. 



MUCRONELLA MENTALIS, n. sp., PI. Y, Fig. 7. 



Zooecia elongated, alternate, in regular lines, separated by 

 deep grooves ; a row of deep rounded areolations or pores 

 along the margins ; surface granular ; mouth arched above, 

 lower lip projecting as a rounded process, bulging below the 

 mouth ; six articulated spines on the upper margin. Ooecia 

 rounded, granular, subimmersed in the cell above. 



Port Phillip Heads. 



Lagenipoea simplex, n. sp., PI. Y, Fig. 8. 



Zooecia much enlarged below, contracted at the mouth, 

 with the produced peristome either circular at the orifice 



