TETHYS—-INDIAN OCEAN. 111 
wide, folded together over the back, nearly covering the mantle 
cavity. Eyes near and in front of the tentacles, small and black, 
with encircling rings of blue. Olive colored, with scattered eye-like 
spots composed of a white center surrounded by a dark brown ring. 
Shell quite thin, transparent, light brown. 
Near Tor, Red Sea, on sea-grass in March. 
Aplysia argus R. & L., Atlas zu der Reise im nordlichen Afrika 
von Eduard Riippell. Neue wirbellose Thiere des Rothen Meeres, 
p. 23, pl. 7, f. 1 (1828).—? Aplusia radiata EHRENBERG, Symb. 
Phys., Evert., Decas 1 (1831), not A. radiata Crouch.—? Aplysia 
scutellata EHRENB., l. c. 
The illustration is drawn and colored from life. I consider A. 
radiata (name preoccupied) and A. scutellata as in all probability 
synonyms, but repeat below the essential characters described by 
Ehrenberg. 
A. radiata Ehrenb. Length 3 inches; olive-green. Outer sur- 
face of swimming lobes and back with brown ocelli with radiating 
black lines ; inner surface of swimming lobes with dull yellow spots 
surrounded with black-brown; labial tentacles scarcely auriculate ; 
mantle ovate, lightly convex, emarginate behind, less than a third 
the total length. 
Tor, Red Sea. 
The color of the three specimens observed was the same, but they 
varied in size, the largest being 3 inches long. Body a soft green, 
subreticulated above with black-brown and black lines, which 
usually radiate from the ocelli, and on the neck are longer and 
longitudinal. Foot brownish-green with sparsely scattered black 
marks ; labial tentacles not produced in hamate ears. This species 
is closely allied to A. argus Leuck., but that species has the labial 
tentacles larger, much dilated and hamate, the eyes encircled by 
blue rings, the inner surfaces of swimming lobes lacking dull yellow 
spots, the radiating lines less distinct, and the mantle proportion- 
ally longer. 
A. scutellata Ehrenberg. Length 14 inches. Dull green, similar 
to A. radiata in the fine strize and black radiated ocelli, but the in- 
ner surface of swimming lobes is pale, clouded with green and 
brown, the tentacles slightly auriculate, and shell ovate, nearly half 
