RHIZOSTOM.E — CEPHEA. 655 



Forskal gives a good, clear drawing of this medusa, which bears so close a resemblance 

 to the figures of " Penrhizii ncmaiophora" of Kishinouye that I am convinced the two are 

 identical. The medusa is distinguished by the very deep rhopalar clefts in the bell-margin, 

 its long tapering mouth-arm-filaments, and brown color. Gmelin erred in calling this M . 

 ociostyla, when he quoted from Forskal, for the latter's Medusa oclostyl/i is very different. 



Bell 100 to 140 mm. in diameter. A large dome at apex of exumbrella, nearly as wide 

 as bell-radius and covered completely with about 30 large, conical, pointed warts, many of 

 which are bent near their pointed ends. The dome is surrounded b\' a wide, shallow ring- 

 turrow, which separates it from the nearly e(|uallv wide, flexible marginal zone of the bell. 

 The 8 sense-organs are set within deep niches in the bell-margin, as is well shown in Forskal's 

 figure. There are 80 to 90 marginal lappets; in each octant 8 or 17 large, oval, velar between 

 Z ver\' small, pointed, ocular lappets: the velar lappe's are united by a web, so that the bell- 

 margin appears to be nearl)- entire. The small ocular lappets are deeply set inward centrip- 

 etal to the margin. 



On the subumbrella a radiatine: inner zone of folded ridges contains the radial muscles, 

 and near the bell-margin is an unbroken zone of circular muscles. Arm-disk octagonal , 

 nearly as wide as bell-radius. The 4 subgenital ostia are very small, compressed clefts. There 

 is a unitary, cruciform, subgenital cavit\-. The arm-disk has no canal-system of its own, and 

 there are no mouths upon its central parts. The 8 laterally compressed, stout, adradial 

 mouth-arms are somewhat shorter than the bell-radius. Their upper halves are nearly 

 coalesced where they arise from the arm-disk, but below they fork and each main branch 

 branches profusely and curves upward. The numerous, frilled mouths are found on the lower, 

 ventral sides of these mouth-arms and their branches. Ihere are more than 100 long, tapering, 

 hollow filaments with pointed ends. The largest of these arise from the arm-disk at the points 

 of origin of the 8 mouth-arms, and they are as long as the diameter of the umbrella and 

 hollow. Forskal figures 16 such filaments all apparently arising from the arm-disk and 

 numerous smaller ones arising from between the mouth-frills on the arms, very much as does 

 Kishinouye 127 years later. 



The nearly circular, central stomach gives rise to 8 ocular and about 40 to 48 interocular 

 radial-canals. The ocular canals are not wider than the others, but they extend straight out 

 to the rhopalia, giving off numerous side branches into the network-zone of the bell; whereas 

 the interocular canals lose themselves in this wide network of anastomosing vessels which form 

 a broad zone extending from near the outer edge of the stomach-cavity to the bell-margin. 

 There is no differentiated ring-canal. The network gives off many blindly-ending branches 

 which extend downward into the radiating muscular ridges of the subumbrella. 



The margins of the velar lobes are brown, but Kishinouye finds that other pans are 

 colorless, although Forskal's medusa displayed some reddish-brown on its bell. Forskal 

 describes this medusa from the Red Sea, and Kishinouye from Misaki, Japan, where it is 

 found in winter. Peron and Lesueur's C. fuscn, from Malabar and northwestern Australia, is 

 probably the same medusa; as is also Diplopilus couthoiivi .Agassiz, i86z (Cont. Nat. Hist. 

 U. S., vol. 4, p. 158), from Hawaii. The medusa appears to be widely distributed over the 

 Indo-Pacific region. Haeckel's C-phra conifern from Samoa may be another name for the 

 same medusa, but its color is not stated and i'.s marginal lappets appear to be indistinct, and 

 the bell-margin to be practicall}' entire, as in C. rcrrulea. The decided resemblance, in other 

 respects, between Haeckel's C. coiiifcra and Forskal's medusa will appear in the following 

 description. 



"Cephea cephea var. conifera" Haeckel. 



Cephca conifera, Haeckel, 1880, Syst. dcr Medusen, p. 576, taf. 36, fign. 3-6.— Hamann, 1881, Jena. Zcit. fiir Naturw., Bd. 15, 

 p. 246 (anatomy of mouth-arms). 



This is probably identical with Cephea eephea. 



Bell 100 to 120 mm. wide, 30 to 40 mm. high. A thick-walled, flatly rounded, central 

 dome upon the exumbrella bears 20 to 30 large and numerous small protuberances and is 

 separated from the marginal zone of the exumbrella by a deep annular furrow. These solid, 

 wart-like protuberances of the central dome are scattered irregularly over its entire surface, 

 as in C. ea'rulea, not arranged in 2 rows, as in C. dumokuroa. 8 rhopalia are set within deep 

 niches. 80 indistinctly developed, marginal lappets. In each octant 8 wide, flat, velar lappets, 



