Cyan^ea. RADIATA. ACALEPHA. 501 
Medusa hemis. Mull. ZooL Dan. t. vii. — Medusa, Cordiiier's Ruins, 
No. xi.— M. hem. Mcu:artney^ Phil. Trans. 1810, 268. t. xv. f. 5. 
Minute, campanulate, the mouth subpedunculated, with five very short 
arms — This species is one of those which are remarkably luminous at night, 
and is very common. 
57. G. octona. — Body round subconical, blunt at the summit, 
and slightly acuminated. 
Flem. Edin. Phil. Journ. viii. 299 At the Bell Rock. 
About an eighth of an inch in diameter ; margin furnished with eight simi- 
lar tentacula, equal to the diameter of the body ; oral disc concave, with the 
central mouth slightly pedunculated. 
Gen. XXII. CYAN^EA Body hemispherical ; mouth with 
arms ; margin of the body with tentacula. 
58. C. aurita. — Convex, translucent, with four incurved se- 
micircular central markings ; mouth with four long crenulated 
and ciliated arms. 
Medusa aurita, iim. Syst. 1197. ATmW. Zool. Dan. t. Ixxvi. — M. cru- 
ciata, Turt. Brit. Fauna, 139. — M. cruciata and aurita, Stewart's El. 
i. 399. — Not uncommon. 
On the dorsal aspect the body is depressedly convex, smooth ; the mar- 
ginal tentacula are thick at the base, interrupted in the circle by eight glo- 
bular organs, with two arms, having a perforated middle process with a black 
point ; the arms do not appear in very young specimens. 
59. C.Jusca. — A brown circle in the centre of the dorsal disc, 
with 16 rays, of the same colour, converging from the circum- 
ference. 
Urtica marina, Borl. Corn. 256. t. xxv. f. 7. — Medusa fusca, Penn. Brit. 
Zool. iv. 57 . — Shores of Cornwall. 
Convex, the circumference with 16 knobs, the termination of the rays 
with intermediate crooked fangs between each ; mouth cruciform. 
60. C. purpurea. — A pale purple cross in the centre, with 
4 incurved semicircular marks, and 16 diverging deep purple 
rays. 
Borl. Corn. 257* t. xxv. f. 9.— Medusa purpurea, Penn. Brit. Zool. iv. 
57 — Common. 
Margin more incurved than the preceding ; rays of the cross pointed ; 
mouth cruciform, with 4 arms. 
61. C. tuherculata. — A granulated central spot, with 16 di- 
verging simple rays. 
Borl. Corn. 257- t. xxv. £ 11.— M. tuherculata, Penn. Brit. Zool. iv. 58. 
— Shores of Cornwall. 
The margin has two tubercles between each ray. The arms are narrow, 
and longer than the body. 
62. C. capillata. — Convex, the margin divided into 16 seg- 
ments. 
