Zoohgij.~] NATURAL HISTORY OF VICTORIA. [Polyzoa. 



Plate 126, Fig. 9. 



SCRUPOCELLARIA ORNITHORHYNCHUS (Wyv. Thomson). 



Description. — Branches of zoarium slender. Zocecia elongated, narrowed 

 downwards ; aperture elliptical, occupying" rather less than half the front, with a 

 thickened margin much wider below; scutum much projected forwards, extending 

 the whole length of the aperture, somewhat pyriform, the upper extremity produced 

 into a narrow point, and turned forwards; a bifurcate or double spine close to the 

 base of the peduncle of the scutum, and 3 or 4 long, slender spines from the outer and 

 upper part of the aperture. Lateral avicularian processes usually very large ; 

 anterior avicularia very small, situated on eminences below the apertures. Vibracular 

 setfe short, slender, smooth. Two vibracular cells at a bifurcation. Ocecia smooth, 

 imperforate. 



Reference.— Wyville Thomson, Dublin, Nat. Hist. Rev., July 1858, p. 144, 

 pi. xii. ? fig-. 2; Busk, Challenger Polyzoa, pt. i., p. 24, pi. xi., fig. 6. 



Port Phillip Heads and elsewhere. 



In some of my specimens it is difficult to discriminate between 

 this and S. scrupea. The chief distinctions are in its smaller size, 

 the more slender zocecia, the extremely long scutum, which is much 

 projected forwards, overlaps the whole length of the aperture, and 

 has the upper extremity pointed and turned forwards. The 

 arrangement of the spines is much the same in both, although in 

 the present they are usually more slender and longer, and the inner 

 one is almost always bifurcate or double. In both, the lateral 

 avicularian process is of considerable size, and there are two 

 vibracular cells in the angle at a bifurcation. The margin of the 

 aperture is usually much more thickened below, and is occasionally 

 slightly tubercular. Thomson describes the scutum as ending in a 

 spine, and figures this as very long. There can, however, be no 

 doubt that this is the species intended by him. 



Explanation of Figures. 



Plate 126. — Fig. 9, specimen, natural size. Fig. 9a, anterior view, magnified ; in this 

 portion the branches at the bifurcation are continuous, not articulated. • Fig. 9b, another portion 

 of the same, showing ocecia. Fig. 9c, dorsal view. 



I am indebted to Mr. MacGillivray for the specimens and 

 descriptions of .the Polyzoa on this plate. 



Frederick McCoy. 



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