STAUnOMBDUS.E — HALIMOCYATHUS. 537 



GENERIC CHARACTERS. 



Stauiomedusae with 4 jKiraclial, pra.stn)<;cnital pockets in the subumhrella wall of the 4 

 stomach-pouches, as in Cleistocaipiii.x. With 8 marginal aiichois (4 periadial and 4 inter- 

 radial). 8 adradial clusters of terminally knobbed tentacles. 4 interradial, horse-shoe-shaped 

 gonads. 8 adradial arms. 



This genus is very closely related to Haliclystus, but is distinguished by the partitions 

 across its 4 perradial stomach-pouches, such as are found in all Cleistocarpidae. 



Halimocyathus platypus Clark. 



Halimocyathui platypus, Clark, H. J., 1S63, Journ. Boston Soc. Nat. Hist., vol. 7, p. 537. — AcASSlz, A., 1865, North Amcr. 



Acal., p. 61. — Haeckel, 1880, Syst. tier Medusen, p. 393. 

 Lucerriaria platypus, Taschenberg, 1877, Zeit. Ges. Naturw., Hallr, p. 92. 



Disk deep funnel-shaped, about 6 mm. wide, and (with the peduncle) 10 mm. in height. 

 The 8 arms are nearly twice as long as broad and one-third as long as bell-height from peduncle 

 to margin. Each arm bears 17 to 20 thick, pistilliform tentacles, about as long as greatest 

 breadth of arms; the tentacles upon each arm are arranged in 5 rows, there being about 7 

 tentacles in the middle row, 4 in each row on either side of the latter, and one in each of the 

 outermost positions. The 8 marginal anchors are small and revetted, being only one-third as 

 long as shortest tentacles, but proportionally broader; their length is a little less than 3 times 

 their radial diameter. The peduncle is about half as high as the disk; at the narrowest part, 

 where it joins the disk, its diameter is nearly half its length, and from there it broadens into a 

 wide base having a width equal to the length of the peduncle; it is round, or very slightly 

 furrowed at 4 points opposite the 4 interradial muscles. The 4 separate, longitudinal chambers 

 of the peduncle are very voluminous and close together, but the longitudinal septa between 

 them are complete. There are 4 horse-shoe-shaped gonads; the centripetal parts of each 

 horse-shoe are united across the inner ends of the 4 interradial parts while the free, outer parts 

 extend to the neighborhood of the marginal anchors. Each arm of the horse-shoe contains 

 15 to 17 genital sacs. The edges of adjacent gonads are joined by a cross partition as in 

 other Cleistocarpidae. 



A single specimen of this species was found by Clark at Chelsea Beach, Massachusetts, 

 where it was found attached to Zoslera, along with H. auricula. It has not been seen since 

 Clark's day, and indeed the contamination of the sea-water in this region has destroyed the 

 StauromedusK which once abounded there, and which are now exceedingly rare along the entire 

 New England coast. 



Halimocyathus lagena Haeckel. 



HolothuTta lagcnam rejerens, MiJLLER, O. F., 1776, Prodromus Zool. Danica, p. 232. 



Lucernaria auricula, Fabricius, 1780, Fauna Groenlandica, p. 341. — Milne-Edwards, 1849, Cuvier, Regne Animal. Zoophytes, 



planche 63, 9 figs. — Sars, M., i860, Forhandl. Vid. Selsk., Christiania, p. 145. — Keferstein, 1863, Zeit. fur wissen. 



Zool., Bd. 12, p. 21. — Taschenberg, 1877, Zeit. Ges. Naturw., Halle, p. 89. 

 Lucernaria fabricii, Agassiz, L., 1862, Cont. Nat. Hist. U. S., vol. 4, p. 176. 

 Lucernaria typica, Greene, 1858, Nat. Hist. Review, p. 132. 

 Manania auricula, Clark, H. J., 1863, Journ. Boston Soc. Nat. Hist., vol. 7, p. 542. — Agassiz, A., 1865, North Amer. Acal., 



p. 62. 

 Halicyathus lagena, Haeckel, 1880, Syst. der Medusen, p. 394.— Levinsen, 1893, ViJ. Meddel. Nat. For. Kjobenhavn (5), 



Bd. 4, p. 147. 



Bell urn-shaped, much deeper than broad. It passes from a rounded base abruptly into 

 the peduncle. Bell about 5 to 7 mm. wide, and (including the style) about 20 to 30 mm. long, 

 A cluster of 60 to 70 slender tentacles upon the end of each of the 8 arms. Arms about as 

 long as broad and grouped into 4 interradial pairs. 8 marginal anchors have the same form 

 as the knobbed tentacles, but are somewhat smaller. 4 horse-shoe-shaped gonads, the distal 

 ends of which extend radially outwards are separated from the bell-margin by a wide space. 

 Each horn of the gonads exhibits 12 to 14 genital sacs. 



Color black or dark brown, rarely reddish-brown or yellowish-brown. 



Found upon the northern .A.tlantic coasts of Europe and upon the coast ot Greenland. 

 It occurs on the New England coast north of Cape Cod, but is very rare. 



