Kill/' ISTOM I) ( <>'n l.ulMIIX A. I',.V.I 



is a single subgenital porticus. The appendages upon the mouth-arms are mounted upon 

 pedunculated filaments. There are 8 marginal sense-organs and numerous radial-canals 

 which anastomose laterally without any definite ring-canal in the adult. The sense-clubs 

 have no ocelli and no exumbrella sensory pit. There is a unitary peripheral zone ot circular 

 muscles and an inner /one ol radial-muscles in the subumbrella. 1 he exumbrella is smooth 

 and without an a bora I "sucker-like" depression, but with a prominent central dome without 

 wart-shaped elevations upon it. 



This genus is sharply separated from (l<issirjf>i-n. with which it has often been confused. 

 by its single, unitary, subgenital ponicus, its relatively simple bifurcated mouth-arms, and by 

 having constantly 8 instead of an indefinite number of marginal sense-organs. Also there is no 

 aboral "sucker" upon the exumbrella, such as is commonly seen in Cassiofea. 



Cotylorhiza tuberculata L. Agassiz. 



Plate 73, fig. 2. 



Medusa tuberculata, MM KI, (!., 1778, Osservazioni Int. Polmonc Marino, p. 20. LlNxt, (Gmdin), 1788, Systcma Natur.r, 

 Ed. 13, Pars. 6, p. 31^. 



Medusa tuber, MACKI, S., 1*25, Aiti Re.ile Acad. Sci. N'ap.ili, MI], 2, Partc 2, p. 74, tav. 4, figs. I, 2. 



Ceplita f>ol\chroma, PERON KT I.* su H'R, 1809, Annal. du Mus. Hist. Nat. Paris, tome 14, p. ^'>i . I, \M\K k, l 81(1, Hist. Anim. 

 sans Vrrt., tome 2, p. 516. 



Cassiofea borbonica, Dnii CIIIAU, iSj-,, Mi-nturie sulla storia e notomia dcgli animali scn/.a vertebre, N.ipi.li, M. in. 3. p. 75, 

 tav. 3, 4, figs. 1-6; 1841 , Animali M n/.i MTI ., N.ip. >li, ti.me 7, tav. 140-141 . KOWAI I VSKY, 1873, Mem. Imp. S 

 of Nat. Hist., Mir i <"., nli 10, part 2, p. 3, plate 2 (Russian). Di> PLTSSIS, 1881, Bull. Soc. Vaud. Sci. Nat., vol. 17, 

 No. 86, p. 633, plate -, i (development i,{ egg-scyphostoma). DE Mv.Rt JKOWSKV, 1882, An l.n . /. 1. I. \pi-r. i-t (Jen. i Ac, 

 tome 10, p.577,planche 29$, figs. 14-20 (development of spermatozoa). CLAUS, 1883, Arbeit, /mil. In r .\\ n-n, H.! . ^, p. i fi.j, 

 2 taf., fign. l-ll (development of the cphyra); 1883, Organisation und Entwick. der Medusen, pp. 4;, ",, t.if. i^, tign. 

 106-1 1 1 (ephyra); 1890, Arbeit. Zool. Inst. VVien, lid. 9, p. 85, taf. 4-6; 1890, Wrhan.ll. /.mil. Bot.m. (iev 11. \Vn n. lid. 40, 

 pp. 54-55 (development "(tin- -i \phostoma lan-a); 1892, Arbeit. Zuol. Inst. VVien., lid. [O, p. I (scyphostoma). GnAErri, 

 1884) Arbeit. Zool. Inst. Wien ( Bd. 5i p. 343 (seasonal distribution). KMIIK, iss^, Rnuiil 2ool. Sui ^tome i.p. 403 

 (breeding habits of the medvis.i, .in. I nature uf the "selluw cells"). VAN HI IK JN, i8S8, liibliothna /.milngira, H.I. i, II. I' ;. 

 pp. 27, 40 (in the Red Sea). Htssi, 1895, Zeit. fur wissen. Zool., Bd. do, p. 441 , tat. 2 I , tie,n. 17-19; taf. 22. lirri. 2-. 28 

 (nervous system of the subumbrella). HII.K LOW, R. P., 1900, Mem. Boston Soc. Nat. Hiet., vol. 5, No. 6, p. ;o.|. 1 1 

 i902,Zool.Anzcigcr,Bd.25, p. 637; 1902, '/.eit. fur wissen. Zool., Bd. 73, p. 302, taf. 20. 2 i ' irula). 



BETHE, 190-,, Allgcmeine An.it. nn.l 1'hvsi.il. Nervcnsystem, pp. 410, 414, 448, etc., fig. 8-,, 84, 8S, i|i. i-tc. (pi. 

 the nervous system and of pulsation). MAAS, 1904, Result. Camp. Sci. Prince de Monacn. t.i . . :S, p. 58, planche 2. 

 figs. 16-19; P' ate '> ^- 47! ! 9" Scvphnm.-dusen der Siboga Expcd., Monog. n, p. -,2, t.il. S, tign. (19,70. Hoi MIK, 

 1907, Bull. Imtit. Oi-e.m.igi.ipli. Pii m e de Monoco, No. 93 . 



( ?) Cassiofea enroll iflora+ C. canariensis, TILKSIUS, 1829, Nova Acta. phys. med. N. C., tome 15, pp. 265, 285, tab. 73. 



Cephea tuberculata, ESCHSCHOLTZ, 1829, Syst. der Acal., p. 56. 



Cefhea wagentri, WILL, 1884, H.ir.i Terge tm.i , p. ;S. Hi s, n, i 851, Anat. Entwick!. \virbell. Seeth., p. 3O,taf. 2, 3. FK^N c/n s, 

 1852, Zeit. fiir wissen. Zool.. H.I. 4, p. 118, taf. S, fign. 1-4 (siphostoma larva). 



Cassiofea borbonica, GH;HM \i u, 18^4. Generationswechsel Medusen, p. i, taf. 2, fign. 32-35- 



Cotylorhiza tuberculata, AI;ASSIZ, L., 18(12. font. Nat. Hist. U. S., vol. 4, p. 158. HAMANN, 1881, Jen.i. Z.-ii. fur Narunu n, 

 B I. 15, p. 254, t.if. <i, fign. 8, 9; taf. 10, fign. 19-23, 34, 35; taf. n, fign. 24-28 (structure of the mouth-arms). 



Cotylorhiza luberculata, and C. ambulacrata ( ') HAM kti , 1880, Syst. der Medusen, pp. 610, hi I. 



Cotylorhiza borbonica, GOTTE, 1 88;, /.....]. An . . U. I. 8, p. 554; 1887, Abhandl. Entwich. ,|. i Ilinir, Heft. 4, Leipzig, 79 pp.; 



1893, Zeit. fur wissen. Zool., Bd. 55, p. 645, taf. 28, 29 (embryology). 



Bell usually not more than 150 to 170 mm. in diameter, though according to \\ ill it may 

 become 300 mm. wide. The dimensions of a large medusa found at Naples on December iS, 

 1907, were as follows: Hell idX mm. wide, arm-disk 88 mm. wide, each mouth-arm 4') mm. 

 long and 54 mm. thick (dorso-ventrally). The gelatinous substance is \ei\ rigid. The exum- 

 brella surface is smooth and without wart-like projections. 



The center of the exumbrella is occupied by a smooth, elevated dome, somewhat flatter 

 than a hemisphere and about as wide as radius of disk. Around the outer edge of this dome 

 is a depressed region forming a gutter-like ring, somewhat lower than the pans ot the bell 

 nearer the margin. There are 8 marginal sense-organs, which lack an exumbrella sensory 

 pit and base no ocelli. The sense-club has a very large, bag-like ventral bulb and contains 

 a terminal mass of orange-colored entodermal concretions. 



The marginal sense-organs are Hanked by in short, blunt, oval rhopalar lappets. Tin it- 

 are typically 1O velar lappets in each octant, the middle d of which are sometimes, but not 

 always, cleft. The outer edges of these lappets are subrectangular with bluntly-rounded 

 angles. The primary clefts lni\\<ni the lappets are fully twice as long as the s<ruml;n\ delis 

 of the 6 middle lappets; but all the clefts are bridged over by a web of subumbi el la tissue, 

 so that they are not complete cuts, but meie grooves upon the exumbrella. 1 he id vel.n 



