124 Transactions of the Canadian Institute. [vol. ix 



endostyle has been displaced toward the left side. Although the loop is 

 sometimes more to the right, sometimes more to the left of a plane passing 

 through the apertures perpendicularly to the disk, it is always on the 

 morphological right side of the pharynx, just as in Corella. It is 

 directed forward, however, instead of transversely. 



C. productum Stimpson. 



Numerous specimens from Departure Bay and Ucluelet and one from 

 Hecate Straits. 



Characteristic of this species are the symmetry of the disk, the large 

 size of mature individuals and the absence of muscle bands across many 

 of the lines between the plates of the disk. 



C. columhianum sp. n. 



Usually flattened and depressed, attached by a broad area on side 

 opposite the disk. Margin of disk sharp, not raised above level of disk. 

 Disk broad behind. Apertures nearer right margin of disk than left. 

 There are typically 2 central, 12 marginal and 2 left intermediate plates, 

 but there is a fairly wide range of variation. Up to 19 mm. in length 

 and 14 mm. in breadth. In addition to the siphonal and marginal 

 muscles, there are short strands crossing all the lines that are some dis- 

 tance from the margin. 



From 50 to 100 tentacles. From 12 to 22 languets. Aperture of 

 dorsal tubercle a transverse slit. Funnel asymmetrical, the duct con- 

 necting with left side of tubercle. From 33 to 42 bars on each side of 

 pharynx. Stigmata more or less coiled, with as many as 2 ^ turns in a 

 coil, irregularly disposed. 



Gastric folds for the most part longitudinal. Intestine narrow. 

 Loop narrow, some distance to right of posterior half of endostyle. 



About 40 specimens from Departure Bay and Burrard Inlet in from 

 10 to 20 fathoms, stony and shelly. 



Easily distiguished from the last by the presence of the series of mus- 

 cle fibres connecting the central plates. It reaches maturity at a much 

 smaller size. It differs from C. sibogae Sluiter of the East indies and 

 Japan, in the irregularity of the musculature, in the coiling of the stig- 

 mata and in the aperture of the dorsal tubercle being transverse instead 

 of longitudinal. 



Family — Ccesiridae [Molgulidae]. 

 CcBsira apoploa sp. n. 



Nearly spherical. Usually free in the sand. Siphons equal, in 

 length about half the diameter of the body. Surface covered with sand 

 grains, with the exception of that of the siphons and a variable part of 

 the surface near them. Long simple radicoid filaments over the sand- 



