FISHES, ETC. OF THE *NASSAU? VOYAGE. 499 
in S. planus, and possessing three well-marked ridges—a median, interrupted in the 
middle, and two lateral, each terminating in a sharp point. Eyes very prominent, and 
placed rather near each other. Two specimens taken on the north coast of Fuegia. 
71. CASSIDINA EMARGINATA, Guérin. (Pl. LIX. fig. 4.) 
This species (described, but not figured, by Guérin in the ‘Icon. Règne Anim., from 
specimens taken at the Falkland Islands) 1 found plentifully on the fronds of growing 
Macrocystis, in the Strait of Magellan and channels on the west coast of Patagonia. 
Only a single unnamed specimen existed previously in the national collection. 
72. SPHÆROMA LANCEOLATUM, White. 
Extremely common under stones and among the roots of Macrocystis in the Strait of 
Magellan and channels. Is this species truly distinct from S. gigas, Leach ? 
73. OYMODOCEA DARWINII, n. sp. (Pl. LIX. fig. 1: o, antenna; b, last joint of first leg.) 
Texture of body calcareous. Dorsal surface rough, with many minute granulations. 
First segment of pereion longer than the others. Fifth enlarged at either extremity, 
each of which bears a blunt spine. Last segment of pleon emarginate at the apex, 
and furnished with a strong short spine. External caudal lamella minute, narrow. 
A very few specimens of this species were dredged on the north coast of eastern 
Fuegia. 
74. IDOTEA ANNULATA, Dana. 
Specimens of this species were taken in the towing-net between Rio de Janeiro and the 
river Plate, and between that river and the Strait of Magellan. 
15. EDOTIA TUBERCULATA, Guérin. 
Taken in the eastern portion of the Strait of Magellan. 
76. EDOTIA MAGELLANICA, n. sp. (Pl. LIX. fig. 6; «a, one of the anterior legs.) 
Body much smaller than that of E. tuberculata, and broader proportionally. No 
dorsal tubercles. Length 7 lines. 
Taken off Cape Espiritu Santo, at the eastern entrance of the Strait of Magellan. 
77. CYMOTHOA GAUDICHAUDII, Edw. 
Taken on a fish, in the Bay of Coquimbo, August 1868. 
78. CERATOTHOA EXOCGTI, n. sp. (PL LIX, fig. 5.) 
Allied to C. linearis, Dana. Body long, linear. Head longer than broad, the front 
prominently projecting. Processes of next segment to head longer than in C. 
linearis. First segment of pereion distinctly exceeding the two following in length. 
Antennæ curved backwards along the sides of the head. Posterior segment of pleon 
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