ZooL.— Vol. III.] ROBERTSON— ASCORHIZA OCCIDENTALIS. 103 



occupied by the muscle plate buds. Fig. 6 is a sketch of a 

 single polypide dissected out from the head. The general 

 shape is that of an ectoproct. The circle of tentacles does 

 not include the anal aperture, but surrounds the mouth- 

 opening only, to the number of sixteen or eighteen. The 

 mouth opens into a pharynx lined by large granular cells; 

 this into a relatively long oesophagus, a sac-like stomach, 

 a short intestine, and rectum. Upon dissection, certain 

 yellowish bodies which appeared on the surface of the 

 head proved to be cihated larv«, two of which occupied 

 a zooecium. Are these the "yellow pigment spots" to 

 which Fewkes refers ? 



Relationships. — From the data which a study of the 

 polypide affords, there is no difficulty in placing Ascorhiza 

 with the ectoproctous Bryozoa. A similar study of the 

 zooecia and their mode of growth as surely places it in the 

 subclass Ctenostomata, and as Fewkes suggests, somewhere 

 near the genus Alcyonidmm. Regarding the capitulum by 

 itself, it would be hard to distinguish it from a very minute 

 colony of Alcyonidmm gelatinosimi, or of A. mytili whose 

 zocecia had become much crushed or crowded together. 

 Fig. 7 is a sketch of a tentacle sheath as seen from the in- 

 side of the capitulum. It is typically Ctenostomatous in the 

 infolding of the tube, its closure by fine bristles {hr.), and 

 by the muscles which form the so-called diaphragm {dta.). 



In his discussion of the relationships of Ascorhiza, Dr. 

 Fewkes seems to consider that the possession of a stalk 

 relates it to the entoprocts, especially to Urnatella, and 

 perhaps to Ascopodaria. He suggests that it may constitute 

 a connecting link between the entoprocts and ectoprocts 

 and thus assist in settling the disputed question of the rela- 

 tionship of these two groups of Bryozoa. From the point 

 of view of the present writer, such a relationship does not 

 exist. The stalked condition, although hitherto unknown 

 in the family Alcyonidiidae, does not constitute a morpho- 

 logical barrier to membership in this family. As will be 

 shown later, at least one other stalked form, belonging to 

 the genus Alcyonidium, occurs on the Pacific Coast. 



