NO. 1989. A8CIDIAN8 FROM NORTHEASTERN PACIFIC— RITTER. 463 



ceus, as having a short peduncle. However, the structure in this 

 case is thick, and is accompanied by other root-like processes. Sluiter 

 does not go into details as to the structure of these parts, but his 

 description and figure would seem to indicate that they are quite 

 different from the peduncle of H, triangularis. 



Atrial tentacles are now known to occur in several quite widely 

 separated groups of ascidians, so that this feature alone would prob- 

 ably not justify a new genus for the species. However, when taken 

 in connection with the peduncle and the unusual supply of epithehal 

 bands around the orifices, it would seem that to assign the species to 

 any known genus would be forcing matters somewhat more than 

 giving it a genus by itself. 



An additional structural point in connection with the atrial ten- 

 tacles may be mentioned. As is shown in figure 12, the attachment 

 of each tentacle is some distance from the periatrial band. However, 

 a minute strand, seemingly epithehal, extends from the root of the 

 tentacle to the band. These strands would seem to be rudimentary 

 and adherent portions of the tentacles. 



I have mentioned the epithehal knobs on the inner surface of the 

 periatrial field in the diagnosis on account of the possibihty that 

 they may be normal growths into which the parasites enter instead 

 of products of the parasitic action. 



Tijpe-locality. — About two dozen specimens taken by Dr. W. H. 

 DaU in 9 to 12 fathoms at Kyska Harbor, Aleutian Islands, Alaska. 



Type.— C&t. No. 5679, U.S.N.M. 



CULEOLUS SLUITERI, new species. 

 Plate 34, figs. 14-17. 



Superficial characteristics. — Body irregularly conical, the base of 

 the cone (posterior end of animal) not flat but sharply arched; only 

 slightly, if at all, compressed, pedimcle attached to apex of cone, the 

 transition from body to peduncle being much the same all around 

 (pi. 34, fig. 14). Branchial orifice at the summit of a broad, low 

 mound situated about one-third of the distance between the insertion 

 of the peduncle proper and the atrial orifice. The opening large, 

 irregularly triangular, the base of the triangle directed forward and 

 constituting an arched lip, smooth, except for a number of fine creases; 

 border of the posterior apical part of the opening irregularly puckered 

 and lobed. Atrial orifice a large transverse slit broadly notched in the 

 middle of the anterior lip, situated far back on the dorsal side of the 

 body. Entire surface covered with low, broad mounds, each of which 

 bears at its summit a wartlike brownish knob, the knobs extending, 

 gradually reduced m size, on to the apex of the body to the point at 

 which the body is lost and the peduncle begins; also a few scattered 

 small warts on the peduncle. Color a dull white, uniform except for 



