Zoology.-] NATURAL HISTORY OF VICTORIA. [Polyzoa. 



Port Phillip Heads ; Wilson's Promontory ; Portland, Mr. 

 Maplestone ; Warrnambool, Mr. Watts. 



This species is of frequent occurrence, and is found in small 

 masses usually attached to Polyzoa and Hydrozoa. The zooecia are 

 very irregular, distinct, and mostly nearly erect. The surface is 

 beautifully fluted, with prominent convex ribs extending from the 

 mouth to the base. These are sometimes thicker above, forming 

 a prominent ridge round the mouth. There are usually two 

 (occasionally more) thick, erect, calcareous processes at the sides 

 of the mouth, either smooth or fluted like the surface of the 

 zooecia. Each is surmounted, towards the inner side, by an oval 

 or elliptical avicularium, with the mandible directed downwards. 

 There are also, occasionally, larger vicarious avicularia, on elevated 

 calcareous processes, with nearly semicircular mandibles. The 

 ooecia are of considerable size, extending nearly horizontally from 

 the upper edge of the mouth. They are rounded, occasionally 

 smooth, but mostly with a sculptured area. These markings are 

 usually shallow, but in old specimens are much deeper and more 

 numerous, and the area then has a sharply defined margin. 



Explanation of Figures. 



Plate 148. — Fig. 2, specimen, natural size. Fig. 2a, portion magnified, showing zooecia 

 previous to growth of oral processes ; one with processes commencing to grow, and the others 

 with one or two fully developed. The ooecia are of the usual appearance. A large vicarious 

 avicularium is seen on the right. 



Plate 148. Fig. 3. 



CELLEPORA ROTA (McG.). 



Description. — Zoarium encrusting-. Zooecia irregularly arranged, nearly erect, 

 more or less globose, surface smooth or pitted ; mouth with a deep sinus in the 

 lower lip ; on each side of the mouth an elevated process, surmounted by a short 

 broad avicularium, the mandible broadly triangular with an obtuse point. Ooecia 

 much raised, with a nearly circular, defined area marked by radiating grooves. 



"Reference. — P. H. MacGillivray, Trans. Roy. Soc. Vict., Dec. 1884. 



Port Phillip Heads. 



Allied to C. costata, with which it has been united by Mr. 

 Waters, but certainly distinct. The zooecia are distinct, little 



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