538; DR THOMAS SCOTT ON THE 
The male differs from the female by the peculiar structure of the right antennule, 
the fifth and sixth joints of which are produced exteriorly into angular and gibbous 
expansions. The seventh joint is elongated and slender, while the base of the next one 
extends inwards into a horn-like projection nearly at right angles to the joint, but curved 
slightly forward and having its inner edge finely serrated. The remaining joints are 
slender and moderately elongated, except the last one, which is short; the articulations 
between the fifth and sixth and the eighth and ninth joints are hinged (fig. 1). 
The fifth pair of thoracic legs in the male are asymmetrical, that on the left side 
is long and slender and terminates in a claw-like spine, while the basal part of the 
proximal joint expands anteriorly into a short angular process. The other foot is also 
elongated, but the end joints are dilated and form a thumb-like arrangement, as shown 
in the drawing (fig. 5). 
Hatbitat.—This species was obtained in gatherings from Stations 64, 65, 67, and 
93,67 3078.,.347.25 Wa, to 30° 0b Goan 8) ye 
Calanopia americana was obtained by Dr Daut in a collection of plankton from 
the mouth of the river Tocantins, on the north-west coast of South America, where the 
water was doubtless more or less brackish. Its occurrence in the Scotza collections, 
besides extending the distribution of the species considerably, is interesting, from its 
having been found in the open sea. 
Genus Labidocera, Lubbock, 1858. 
Labidocera ner (Kroyer). 
1848, Pontia nerit, Kroyer, Naturh. Tidsskr, (N.S.), vol. ii. p. 579, Taf. 6. 
This was a tolerably common species in the Scotza collections. It occurred in no 
fewer than twenty-eight gatherings, extending from Station 7, 26° 23’ N., 20° 20’ W., 
in the North Atlantic, to 95, 32° 15’ S., 47° 30’ W., in the South Atlantic, occurring at 
nearly regular intervals. 
Labidocera acutifrons (Dana). 
1849, Pontella acutifrons, Dana, op. cit., vol. ii. p. 30. 
The only gatherings in which this species was obtained were collected at Station 
14, 21° 28’ N., 22° 40’ W., and Station 18, 19° 59’ N., 23° 34’ W. 
Genus Pontella, Dana, 1849. 
Pontella atlantica (M.-Edw. ). 
1840, Pontia atlantica, M.-Edw., Hist. Nat. Crust., vol. viii. p. 420, Taf. 39, 
This species occurred in gatherings from Stations 7, 35, and 41, 26° 23° N., 20° 
20' W. to 5° 40’ N., 26° 4’ W., but only a few specimens were observed. 
a ee ee Se 
