EEPOET ON THE POLYZOA. 
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The proper generic position of this species is also extremely doubtful. The tubular 
peristome in the youngest zooecia suggests an affinity with Tessaradoma, but there is no 
median pore, and the mouth is apparently that of a Myriozoan, although if the primary 
mouth could be seen it would probably be found to correspond in form with the very 
delicate operculum, which I have succeeded in isolating, and found to be semicircular 
with a straight entire lower border. The solid texture of the cell walls which are 
obscurely punctate, and the entire absence of any avicularian organs, are strongly against 
placing it with the typical Myriozoa. 1 do not however venture to make a new genus 
for its reception, and have therefore provisionally placed it under Myriozoum. 
(4) Myriozoum marionense, n. sp. (PI. XXIII. fig. 6). 
Character. — Zoarium continuous, composed of long straggling cylindrical branches 
of uniform diameter, divaricating irregularly usually at right angles, occasionally anas- 
tomosing and constricted at irregular intervals. Surface in the natural state polished 
and covered with a plumbeous-coloured thick epitheca, beneath which it is punctate with 
elongated pores. Zocecia completely immersed, with no visible outlines, disposed quin- 
cuncially on all sides of the branches. Orifice completely immersed, looking directly 
upwards, transversely elliptical anterior border thin, entire. A small avicularium with 
a spatulate mandible on each side just within the border of the orifice. No visible 
operculum. Ooecia 0. 
Habitat . — Prince Edward Island, 80 to 150 fathoms. Station 151, off Heard Island, 
75 fathoms, volcanic mud. Station 148, lat. 46° 47' S., long. 51° 37' E., 210 to 500 fathoms, 
hard ground, gravel and shells. Off Marion Island, 50 to 75 fathoms. 
I place this very peculiar form under Myriozoum chiefly on account of its external 
habit which is exactly like that of that genus, especially as shown in Myriozoum coarctatum. 
But in other and more essential characters it differs so widely from the typical forms of 
the genus that its collocation with them must be regarded as entirely artificial. 
The collection affords abundance of specimens in perfect preservation, but notwith- 
standing numerous attempts at decalcification I have been unable to detect a trace of an 
operculum, which I thence conclude must either be entirely membranous and very delicate, 
or perhaps wholly deficient. 
12. Haswellia , n. gen. 
Myriozoum, sp., Haswell. 
Character. — Zoarium composed of short cylindrical branches, spreading in all 
directions dichotomously, at very open angles. Zooecia disposed verticillately and more or 
less irregularly quincuncial, with a produced tubular or subtubular and bifid, or simply 
