ANTIIOMKDI S.K -TVHKITol'SIS. I I.'! 



Genus TURRITOPSIS McCrady, 1856. 



OfCiiniti (Turritopsisjj M<C'RADY, 1856, Proc. Elliott Soc. Charleston, p. i. 



MtiJcrriii, FKWKKS, 1881, Bull. Mus. Comp. Zool., vol. 8, p. 149. 



Turrilofiis, MI-CRA.DY, 1857, Gymn. Charleston Harbor, p. 24. HAI.C-KM., 18^9, Svst. d.-r Medusen, p. 65. BROOKS. i*S;. 

 .Studies Biol. Lab. Johns Hopkins Univ., vol. 2, p. 465. BROOKS, 1886, Mem. Boston Soc. Nat. Hist., vol. 3, p. 387. 

 HARTLAIJB, 1897, Meeresuntcrsuch., Helgoland, Neue Folge, Bd. 2, Heft, i, Abt. 2, p. 480. VAMHHM >, iXiji. /,.,,il. 

 Anzeiger, Bd. 14, p. 444. BROOKS and RITTENHOI si, 1907, Proc. Boston Soc. Nat. Hist., vol. ;-,, p. 4;!.. 



\on Turritopsis, AGASSIZ, A., 1865, North Amer. Acal.. p. 167. 



The type species of this genus is T . nutrient a McCrady, 1856 -57, from Charleston I larlior. 

 South Carolina. It is common in summer from the West Indies to the southern coast of New 

 England. 



GENERIC CHARACTERS. 



Margelinae with S or more simple, marginal tentacles, which arise singly, not in clusters, 

 from the bell-margin. The walls ot the 4 radial-canals, above the stomach, consist of highly- 

 vacuolated, entodermal cells, forming a peduncle for the gastric part of the manubrium. The 4 

 lips are studded with nematocyst-hearing knobs. The gonads are developed upon the 4 inter- 

 radial sides of the stomach. The hydroid is Dendroclava. 



Turritopsis is peculiar in the remarkable development of vacuolated, entodermal cells 

 lining the courses of the 4 radial-canals above the stomach. This condition is also displayed 

 to a limited degree by some, but not by all, ot the medusae of the genus Lymnorea. In Lvi- 

 nnrt'ii, however, the mouth is surrounded by branched, oral tentacles, whereas in Titrritnfi> 

 the lips display bead-like knobs of nematocysts, which I am inclined to regard as the remnants 

 of the oral tentacles of the ancestral forms of Turritopsis. The tentacles of Turritopsis arc 

 solid and similar in structure to those ot Lymnorea. There is an ectodermal ocellus upon the 

 inner (axial) side ot each tentacle, adjacent to the basal bulb. In Tiannje, on the other hand, 

 when ocelli are present they are found upon the outer fabaxial ) sides ot the tentacle-bulbs. On 

 account of the close similarity between the tentacles of Turritopsis and those of (),,,inin, 

 Lymnorea, Podocoryne, Cytteis, znd Cubogaster, we incline to Vanhbffen's (1891) view that 

 T urritopsis is related to the Margelinae rather than to the Tiarina.-. 



Turritopsis is closely related to Oceania, but is distinguished by its \acuolated peduncle, 

 that of Ofcanta being solid and gelatinous. 



Turritopsis nutricula McCrady. 



Plates 14 and 15, figs. 10 to I}. 



Oftania (Turritopsis) tiutricula, McCfiAuv, 1856, Proc. Elliott Soc. Charleston, pp. i-;6, plate 4, figs, i -10. 



Turritopsis nulricula, MiCRADY, 1857, Gymn. Charleston Harbor, p. 25, plate 8, fig. i . BROOKS, iSS;, studies Johns Hopl.m 

 Univ. Biol. Lab., vol. 2, p. 465. BROOKS 1886, Mem. Boston Soc. Nat. Hist., vol. ; p. ;SS. plate ;?. -HAROITT, 1904, 

 Bull. I'. S. Bureau of Fisheries, vnl. 24, p. }7 (the figure is I 3 odo(or\nt earned). Rm'tNiMH s>, M>O^, Pnn . Ii.i'f.,n s.,, . 

 Nat. Hist., vol. 33, p. 437, plates 30-35, figs. 1-55 (development). 



.U"./<vn<; mullitentacula, FKWKKS, 1881, Bull. Mus. Comp./ool. at Harvard Collrp-, \nl. S, p. 141), pi. tic ^, figs. 7-9. 



Mvtlrctiii nutrictiiti, FKWKLS, 1882, Bull. Mus. Comp. 7<ool., \D|. ), p. 2<K- 



non Turritofsis nulricula, AI.ASSIZ, A., 1865, North Amer. Acal., p. 167, figs. 269, 270. 



Turritopsis nulricula (in part), HAF.fKti., 1879, Syst. der Medusen, p. 66. NtTTiN(., 1901 , Bull. I . S. Fish C'nnmiss!<.n. \il. i ). 



P- 375- 



EL Roi-h AN MMH SA. 



Oti-iinia polvfirr hti, KH-KRSTUN, lSfi2. X,eit. fur \vissen. Xool,, Bd. 12, p. i'i. taf. 2, figii. II i;. 



Turritopsis potvnttmi, HAF.CK>L, 187"). S\st. dcr Mi'ilusen. p. (>tt. 



Turrilrjptrs f>rjl\'t irrlia, HARTLAUB, 1897, Wis.sen. MecresunterMiili . K "1111111 .. MI rr< Kir I, H<-|L;"|,UI.|. \' ur I "lee, Bd . 2, p. 480, 



taf. l6r, fig. 2. 

 ( ) r\/,r/.t /)d/v5/\//;, \\'N.I., 1844, Hone Tergcst in.r, p. 68, taf. 2, fig. V. 



.hncriian IHK/HSH ( plate 14, fig. 10). Bell usually slightlv pvritorm and about 4 to , mm. in 

 height. Bell-walls uniformly thin. There are 40 to 70 simple, marginal tentacles, which are all 

 ot about the same length and are somewhat shorter than the bell-height. T hese tentacles are 

 capable of much contraction or extension. Their basal bulbs are large and there is a single, 

 ectodermal pigment-spot upon the lower (centripetal) side of each tentacle near its place of 

 origin from the basal bulb. The surface of the tentacles i> co\i-ied thickly with nematoc\st- 

 cells. The velum is well developed. There are 4 straight, narrow radial-canals and a narrow 

 circular vessel. The manubrium is large and fills about halt of the bell-cavity. The upper 



