158 
“ TERRA NOVA ’’ EXPEDITION. 
Richard and by Hansen. Since Rio de Janeiro Harbour is the type-locality for 
P. avirostris, Dana, our specimens taken a few miles away practically fulfil the 
condition laid down by Richard (1905, p. 10) for the identification of his species with 
that of Dana, and there seems to be no need to wait for further specimens from the 
Straits of Suncla before withdrawing P. oriented is, Dana, also as a synonym. 
The genus Penilia, therefore, appears to include only a single known species which 
has been recorded from Beaufort (North Carolina), Vera Cruz (Gulf of Mexico), Rio de 
Janeiro, Mediterranean off S.E. Spain, Trieste, the Black Sea, various localities in 
the Gulf of Guinea as far south as Loanda, Durban, Straits of Sunda, Hong Kong, 
Port Jackson, Auckland, and Bay of Islands. It seems to be strictly neritic or coastal 
in habitat, and, as Leder has shown, it is tolerant of large changes in salinity. With 
the exception of its occurrences at Trieste and in the Black Sea, and possibly also of 
the New Zealand stations, its range to north and south is limited by the mean annual 
surface isotherms of 18° C. 
nn.ti. ibk 
25. Eradne terc/estina, Claus. 
Evadne ten/estina, Claus, 1877, p. 140, pi. v, figs. 15—16, etc. ; Hansen, 1890, p. 11 : Juday, 
1907, p. 157, fig. ; Scott, 1912, p. 580. 
E. aspinosa , Kramer, 1895, p. 222, pi. xxii, figs. 1—8. 
1 E. gibsoni, Brady, 1914, p. 2, pi. i, tigs. 1-5. 
Occurrence. —Station 89. Six miles off mouth of Rio de Janeiro Harbour. 
Plankton at 2 metres depth. One specimen. 
Remarks. —The solitary specimen appears to belong to this species, with which 
it agrees in the numbers of setae on the exopodites of the legs. It presents, however, 
a slight but distinct notch on the dorsal edge behind the cervical organ, as in Bradv’s 
figure of P. <jibsoni, a species which may prove to be identical with the present one. 
P. terc/estina is known from many localities in the Tropical and South Atlantic, as well 
as from the Mediterranean, the Indian Ocean, Australia, New Zealand, and Southern 
California (Hansen, 1899, and later references given above). 
2C>. Pvadne spinifera, P. E. Muller. 
Evadne spinifera, P. E. Muller, 1868, p. 225, pi. vi, figs. 11—13 ; Claus, 1877, pi. vi, fig. 21 ; 
Hansen, 1899, p. 10 ; Lilljeborg, 1900, p. 647, pi. lxxxvi, fig. 18, pi. Ixxxvii, figs. 1-3; 
Apstein, 1910, p. 43 ; Scott, 1912, p. 580. 
Occurrence.-—Station 17. 2(5 17'N., 20 54' W. Plankton, at 10 metres depth. 
Many specimens. 
IV'PddlMi'l Station G5. 28 28' N., 34 45' \V. Plankton, surface. Two specimens. 
■ • - HfP Remarks .—According to Hansen, this widely-distributed species is especially 
characteristic of and abundant in the central southern area of the North Atlantic. 
Apstein states that its occurrence in the oceanic plankton is associated with the 
presence of Sargasso weed. 
