Meduse of the Philippines and of Torres Straits. 175 
meduse taken in the Philippine Islands at Mactan, near Cebu, on April 6, 
1908, by the United States Bureau of Fisheries steamer Albatross. All were 
mature. 
Vanhoffen (1913) reported that he succeeded in demonstrating that a 
marginal ring-canal is present in the Atlantic L. unguiculata, although after 
many tests I was unable to detect its presence and am inclined to believe that 
the delicate membrane separating adjacent pouches was broken in Vanhoffen’s 
specimens, which were preserved in formalin. Moreover, Vanhéffen found 
that in some of the Atlantic medusew from the Bahama-Florida region the 
subumbrella warts are arranged as in L. aquila of the Pacific. It thus appears 
that the Pacific form is at best only a variety of the Atlantic species, and both 
should be called Linuche unguiculata. 
Genus ATOLLA Haeckel, 1880 sensu Fewkes. 
Atolla, HarckrL, 1880, Syst. der Medusen, p. 488.—Frwxes, 1886, Report Commissioner of 
Fish and Fisheries of U. S. for 1884, p. 934.—Mayer, 1910, Meduse of the World, vol. 3), 
p. 561.—Browng, 1910, National Antarctic Expedition, Nat. Hist., vol. 5, Coelenterata, 
V, Meduse, p. 47. 
GENERIC CHARACTERS. 
Coronatz with numerous (9 or more) tentacles and equally numerous 
marginal sense-organs. Twice as many marginal lappets as sense-organs. 8 
adradial gonads and 4 interradial subgenital ostia. 4lips. The tentacles and 
marginal sense-organs alternate regularly, but the insertions of the tentacles 
and their pedalia are higher up on the sides of the exumbrella than are the 
insertions of the pedalia of the sense-organs. 
The Albatross collection serves to show that A. wyvillei and A. bairdii are 
closely related if not mere extremes of an intergrading series of one and the 
same species. For example, two specimens from station D 5652 in the Gulf 
of Boni, depth of 525 fathoms, have the margin of the central lens distinctly 
notched with radial furrows as in the typical A. wyvillei; but there is an 
annular ridge on the outer side of the ring-furrow with a plain peripheral 
margin as in A. bairdii. Also several other specimens show such very slight 
notches in the margin of the central lens that if one were not looking carefully 
for this feature it would surely pass unobserved and the medusa would be 
called A. alexandri. A large specimen of A. gigantea, from a depth of 519 
fathoms in Buton Strait, shows affinities with A. wyvillei, A. bairdii, and A. 
verrilliz. Thus the margin of its central lens is irregularly notched as in A. 
wyvillet, but without radial furrows. There is an annular ridge upon the 
outer side of the ring-furrow, and the outer edge of this ridge is simple and 
entire, as in A. bairdii, in about two-thirds of its circumference, and notched 
as in the typical A. gigantea in the remaining one-third. The central lens is 
more than half as wide as the medusa, as in A. bairdii, A. verrillii, and A. 
valdivie. 
It is evident that intergrading conditions prevail to a hopeless degree among 
many of the so-called ‘‘species” of Atolla. In fact, I think there are but two 
well-distinguished species: A. bairdii with smooth exumbrella and A. chuni 
with well-developed and quite regularly arranged papille upon the exumbrella 
sides of the lappets. As a matter of convenience, however, we may distinguish 
A. bairdii var. wyvillei by the notched margin of its central lens, and the 
absence of a well-marked annular ridge on the outer side of its coronal furrow; 
for while there is often an annular ridge on the outer side of the ring furrow, 
the margin of the central lens usually projects over it, overarching and con- 
cealing it from view. A. bairdii is a case where this ridge is so well developed 
that it projects beyond the margin of the central lens. 
