Polyzoa of Queen Charlotte Islands. 27 



(without denticles), peristome raised, especially at the back 

 and in front, where it rises in the centre into a blunt mucronate 

 projection, which bends slightly inwards ; the surface of the 

 peristome smooth, entire, and very glossy. Avicalaria 

 none. Ooecium (?). 



Houston- Stewart Channel, not uncommon on shells. 



Mucronella prcelonga, n. sp. (PI. IV. fig. 2.) 



Zocccia long and (usually) slender, quiucuncially disposed, 

 somewhat wider above than at the base (elongate-ovate, some- 

 times appearing almost subtubular), convex, depressed below, 

 rising toward^ the oral extremity ; surface thickly covered 

 with minute punctures, shining (the glistening appearance 

 due to the presence of an epitheca) ; orifice suborbicular, peri- 

 stome elevated round it, carried out in front into a very pro- 

 minent process, often much thrown back and greatly elon- 

 gated, sometimes simply pointed, sometimes bi- or trimucro- 

 nate, on the inner side of it near the base a single, small, 

 sharply-pointed denticle ; the upper margin produced in the 

 centre into a tall spinous process, broad at the base, attenu- 

 ated and membrano-calcareous above. Avicularia none. 

 Ooecium (?). Zoarium forming a whitish subcircular crust. 



Houston- Stewart Channel, on shell. 



A very picturesque form, distinguished by the remarkable 

 processes on the upper and inferior margins of the peristome. 

 The mucro in front is sometimes very greatly elongated, and, 

 in such cases, the upper portion seems to be formed of very 

 delicate membrano-calcareous material. The spinous exten- 

 sion of the peristome on the upper margin, wdiich is much 

 attenuated above, is also made up, to a great extent, of similar 

 material. The subtubular character of the zooecia is a striking 

 feature, though occasionally, and especially near the growing 

 edge of the colony, they assume a more distinctly ovate form. 



Mucrondla spinosissima, Hincks, form major^ 

 (PI. III. fig. 3.) 



Zooecia broad-ovate, short, arranged in quincunx, very 

 convex, sutures deep, surface smooth, subhyaline in the 

 younger cells, opake in the older, a number of slender tubules 

 immersed in the cell-wall immediately beneath the surface, 

 and radiating from the margin towards the centre, the 

 aperture opening out apparently on the surface, but closed by 

 a calcareous diaphragm ; the oral extremity of the cell much 

 raised, contracted, suberect, forming a neck which bears the 

 orifice; orifice suborbicular, a small mucronate projection in 



