Zoology.^ NATURAL HISTORY OF VICTORIA. [Pul^zua. 



Plate 196, Figs. 7-10. 

 RHYNCHOPORA BISPINOSA (Johnston sp.). 



[Genus RHTNCHOPORA (Hincks). (Sub-kingdom MoIIusca. Class Polyzoa. Order 

 Infundibulata. Sub-order Cheilostomata. Family Escharidae.) 



Gen. Char. — Zoarium encrusting. Zooecia closely adherent to each other. Primary mouth 

 transversely elongated, straight, or with a slight sinus in the lower lip ; secondary mouth with 

 a prominent mucro on the lower margin, and an uncinate process immediately above it within 

 the mouth.] 



Description. — Zoarium encrusting'. Zocecia when young' ovate or pyriform, 

 distinct, and horizontal ; when older becoming' small, confused and indi.stinct; 

 sometimes perforated at the marg-ins; surface usually smooth but occasionallj' rough 

 or tubercular. Primary mouth transversely elliptical, ivith a very slight sinus in the 

 lower lip and two straight, articulated spines (mostly absent) above. Secondary 

 mouth rounded, with an uncinate process within towards one side; a transverse 

 suboral avicularium, with pointed mandible on the anterior part of a mound-like 

 elevation, or a prominent mucro. Other smaller avicularia on elevations on the front 

 of the zooecia. Ooecia prominent in the younger parts, but becoming subimmersed 

 or immersed in the older, with the orifice closed by a calcareous operculum. 



Reference. — Rhynchopora hisinnosa, Hincks, Brit. Marine Polj'zoa, p. 385; 

 pi. xl., figs. 1-5. 



Port Phillip Heads. 



This peculiar species is exceedingly variable. The oral spines 

 are very rarely present. As growth proceeds in the young cells 

 an uncinate or anvil-shaped process is developed towards one side 

 of the mouth and usually a smaller more erect process from the 

 othei', the two frequently forming a complete or neai-ly closed 

 round opening. Below or on the fi'ont of the uncinate process a 

 large transverse avicularium is formed on a mound-like elevation, 

 or in its place a prominent rostrum, or very rarely both. In many 

 specimens no avicularia are found. In the usual condition of the 

 older parts, the zooecia are smaller, indistinct, with the mouth large, 

 roundish, and the lower edge with a large transverse avicularium 

 obscuring the parts within. In many zooecia, especially the older, 

 there are one or more smaller horizontal avicularia on large 

 elevations. These, however, as well as the oral are not in- 

 frequently altogether absent. The peristome may be produced 

 into one or more processes on either side. The suboral rostrum 



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