350 



HYDROIDiE. 



Part IV. 



Gonionemus A. Ag} 



G. vertens A. Acf? — Gulf of Georgia, Washington Territonj (A. Agassiz). 

 5th Family. Laodiceid.e Ag. — Tbaumautiadae Gegenh? 



Laodicea Less} — Cosmetira Forbes. — Thaumantias Gegenh. (non Esch.). 

 L. cruciata Ag. — L. crucigera Less. — Medusa cruciata ForsJc, PI. 



33, fig. A. — Oceania cruciata, in Wagner's Icones Zoot., PI. 



33, fig. 2. — Oceania cacuminata Esch. — Thaumantias Mediter- 



ranea Gegenh., PI. 8, figs. 1-3. — Thaumantias corollata Leitck., 



PI. 1, fig. 11. — 3Iediterrunean (Forskal). 

 L. stauroglypha Ag. — /Equorea staurogl^qjha Per. and LeS. — 



Thaumantias (Cosmetira) pilosella Forbes, PI. 8, fig. 1. — British 



Channel (Peron and LeSueur). 

 L. cellularia A. Ag!" — Gulf of Georgia, W. T. (A. Agassiz). 

 L. calcarata A. Ag^ — Naiishon, Buzzard's Bag (A. Agassiz). 



* Gonionemus A. Ag. Spherosome conical, ova- 

 ries in alternate folds along the chymiferous tubes. 

 Digestive cavity flexible ; tentacles attached to the 

 circular tube by a peduncle, not numerous. 



^ Gonionemus vertens A. Ag. Spherosome rather 

 conical, vfith rounded apex, chymiferous tubes making 

 a sharp bend above the commencement of the 

 ovaries, which are dark violet, as well as the ten- 

 tacular bulb, and a spot of the same color near 

 the extremity of the tentacles; the tentacles them- 

 selves are reddish brown, short, sickle-shaped (when 

 the Medusa is in motion), with a bulb wliich is 

 not immediately at the base of the tentacle : tliey 

 can expand to twice the diameter of the Medusa. 

 There are fifteen between every two chymiferous 

 tubes, and one opposite each. The lasso-cells are 

 arranged in rings around the tentacles. The 

 digestive cavity, hanging like a long bag, with four- 

 lobed lips round the actinostome. Vertical diam- 

 eter nine tenths of an inch, actinal diameter eight 

 tenths of an inch. — Gulf of Georgia (A. Agassiz). 



^ As the genus Thaumantias Gegenh. does not 

 correspond to that of Eschscholtz, while it is 

 synonymous with Laodicea Less., this name cannot 

 be retained for the family. 



* By a strange mistake the name of Laodicea 

 is introduced among the synonyms of Aurelia, p. 159. 

 It was copied from a memorandum made to com- 



pare Medusa cruciata Forsk., which is a Laomedea, 

 with Medusa cruciata Bast., which is an Aurelia. 



^ Laodicea cellularia A. Ag. Digestive cavity 

 very short ; lips of actinostome narrow, with frilled 

 edges, at least five times as long as tlie diameter 

 of the digestive cavity. Ovaries extending the whole 

 length of the chymiferous tubes, with a slightly 

 lobed outline. Tentacles very contractile, with a 

 large swelling at the base. Ovaiies and digestive 

 cavity of a light violet color; the tentacular bulb of 

 a darker shade ; the whole spherosome with a light 

 violet tinge. Diameter, across the circular tube, 

 one and one fifth of an inch. Height, three quarters 

 of an inch. Surface of spherosome covered with 

 large, polygonal epithelial cells. — Gulf of Georgia, 

 Wasliington Territory, July to September (A. Agassiz). 



^ Laodicea calcarata A. Ag. Spherosome perfectly 

 transparent ; ovaries hanging in folds from the base 

 of the digestive cavity to a short distance from 

 the circular tube. Digestive cavity sliort, with 

 four thin, wavy lips, equalling in length the diam- 

 eter of the digestive cavity. The tentacles are 

 exceedingly numerous, and placed close together ; 

 from the narrow intervals between them protrude 

 small, solid, club-shaped tentacles, and thread-like 

 cirrlii. The large tentacles have a conical spur, 

 equalling in length the diameter of tlie tentacular 

 bulb, which is of a dirty yellow color, with a dark 



