500 
RADIATA. ACALEPHA. 
Velella. 
Gen. XIX. VELELLA. — Body gelatinous, with an obliquer 
ly inserted prominent dorsal crest ; oral disc flat. 
52. V. limhosa . — Body oval, blue ; oral disc with numerous 
short white filiform tentacula, those of the margin long, une- 
qual, filiform. 
Holothuria spirans, Forskael^ Desc. On. 104.-— V. lim. Lamarck, Hist. ii. 
482 — Barnstaple, Dr Leach. 
Body attenuating dorsally, bluish ; the crest is suborbicular, compressed, 
veined ; the oral tentacula are thickest in the middle. An imperfect example 
of a Velella, which Dr Leach considered as the limhosa of Lamarck, was oblig- 
ingly communicated many years ago. 
53. V. pocillum . — Body round, white, with a broad striated 
bluish border ; oral disc with unequal clavated blue tentacula ; 
the margin crenulated. 
Medusa pocillum, Mont Linn. Trans, xi. 201. t. xiv. f. 4.— Coast of 
Devon. 
Body campanulate ; crest subovate, striated, compressed, and extremely 
thin ; there are about 10 large clavated tentacula, and many intermediate 
smaller ones. 
Dr Walker, in his MS. adversaria for 1771 states the Medusa velella of Lin- 
naeus, as having been found at Ose in Sky ; and Mr Pennant in his “ Caledo- 
nian Zoology,” prefixed to Lightfoot’s “ Flora Scotica,” vol. i. 66. notices 
the same animal without any remark. It is impossible to determine with 
certainty to which of the modern species these references belong. 
Gen. XX. EULIMENA. — Body pouch-like, the mouth large, 
with a simple margin. 
54. E. quadrangularis. — Lengthened, subquadrangular, the 
oral extremity truncated, the opposite end rounded. 
Flem. Edin. Phil. Journ. viii. 302.— Pentland Frith. 
Length about an inch, breadth half an inch ; transparent; 8 minute ciliat- 
ed ribs from the crown to the margin ; the oral disc smooth, having the 
mouth in the form of a transverse slit, leading into an apparently simple 
central cavity. When active, the ciliae are in constant motion, and the body 
frequently assumes the form of a quadrangular prism. 
Gen. XXI. GERYONIA. — Hemispherical, margin with ten- 
tacula, the mouth central. 
55. G. equorea. — Orbicular, depressed, with a villous inflected 
margin, bearing tentacula. 
Medusa eq. Mull. Prod. 233. Jameson, Wern. Mem. i. 558— North of 
Scotland. 
56. G. hemisphcerica . — With four transverse ribs, enlarged 
towards the circumference. 
