1903.] MEDUS/E FROM BRITISH COLUMBIA AND ALASKA, 181 



same depth as the oral peduncle, being very wide at the top, 

 almost half the diameter of the bell. Mouth miich lobed, the 

 lobes being narrow, pointed, and finely toothed. There are half 

 as many lobes as there are radial canals. Thei'e are about a 

 hundred radial canals ; these run from the peripheral canal inwards 

 and upwards to the highest point of the stomach. Each radial 

 canal is covered on its outer sui'face by a ridge of glandular 

 cells. Sometimes these are continued over the stomach and 

 oral peduncle down to the lobes of the mouth, giving an appear- 

 ance similar to that presented by the ovaries of Orchistoma. The 

 two kinds of umbrellar papillae are present. 



Colour, — Organs and bell-margin white, Avith a very slight trace 

 of blue in the larger tentacles. 



Habitat. — Victoria Harbour, Esquimalt Harbour, collected by 

 Shearer ; Pleasant Beach, collected by Kincaid. 



Discussion. — On first examination this Medusa was taken to 

 be Orchistoma. That it is an undoubted ^^quoiid is borne out 

 by the presence of marginal vesicles, of which there are one or 

 two between successive tentacles, the absence of eye-spots, and 

 the presence of excretory papillte under the velum. The papilla? 

 which ai'e in the same row as the tentacle -bulbs are young 

 tentacles. Brandt describes (6) bodies on the inner side of 

 the bell-margin which Haeckel is probably right in considering 

 to be excretory papillae. Brandt speaks of them as follows 

 (p. 361): — "An der innern Seite der Basis des Saumes findet 

 sich eine Anzahl kleiner, tassenformiger, an Gestalt der Cupula 

 einer Eichel nicht unjihnlicher Korperchen." No mention is 

 made as to their relation with the circular canal, and Brandt 

 thinks they are the rudiments of a third row of tentacles. 

 Evidently Mertens did not observe whether they were inside the 

 velum, and pei'haps his remarks refer to the young tentacle- 

 buds we have described above in M. victoria, and not to the true 

 excretory papillse under the velum. Some slight confusion has 

 ai'isen over the position of these papillae. Haeckel (18) and 

 Hertwig (21) describe umbrellar papillee, which are outside the 

 velum (centrifugal), which are, according to them, blind tentacle- 

 bases, or spurs, possessing no openings. Distinct from these 

 are the subumbrellar papillae, inside (centripetal) to the velum, 

 arranged one opposite each marginal tentacle-spur on the outside ; 

 they are connected by an opening at their apex with the circular 

 canal of the bell-margin, and have been interpreted as excretory 

 in nature. Haeckel (18) expressly states (p. 119) that they are 

 inside the velum, and thus in the subumbrellar cavity ; yet in 

 pi. xi. fig. 13 of the same work he shows them as if they were in 

 the same row with the tentacles on the external surface of the 

 bell-edge, and thus outside the velum ; from his figure it is 

 impossible to make out their true position under the velum*. 

 Mayer (28) has described centrifugal excretory papillae on the 



* Since the above was written, it has been found that Clans (10, p. 13) makes 

 practically the same comment, although his figures 29 and 30 are not clear. 



