: of the Fishery Board for Scotland. - 231 
recorded as British by Conrad Beck in the Journal of the Microscopical 
Society for December 1883, and is there described and figured. Herrick, 
in Crustacea of Minnesota (1884), states that it ‘is not yet recognised in 
‘ Minnesota, but was found by Professor Birge in Lake Michigan.’ 
Latona is distinguished from other British Cladocera by, among other 
characters, the structure of the posterior antennee. The inner branches of 
these appendages are two-jointed ; the distal portion of the basal joint next 
the outer branch, is continued forwards in a leaf-like process to fully half the 
length of the second joint, as shown in the figure. The Loch Morar 
specimens were small—-under 1 mm.—but the size appears to vary. 
Mr Conrad Beck states that specimens 2°5 mm. (th of an inch) ave 
often obtained.* 
Family HoLopepipz. 
Genus Holopedium, Zaddach. 
Holopedium gibberum (Gaddach). 
1855. Holopedium gbberum, Zaddach, Wiegman’s Archiy. fiir 
Mapurces. bd. xxt. p,.1o9, PL VILL to, 9, 
This remarkable species was common in Loch Morar, and especially so 
ner the surface of the water. It appears to be widely, but perhaps not 
generally, distributed. In the Fishery Board’s Ninth Annual Report 
there are records of its occurrence in Loch Ness, Loch Oich, and Loch 
Lochy, Inverness-shire. It is distinguished by the greatly elevated and 
hood-like form of the brood-pouch. They frequently measure over an 
eighth of an inch from the apex of the brood-pouch to the under side of 
the body. When seen adhering to the tow-net after being removed from 
the water, they closely resemble at first sight the little medusiform gono- 
phores sometimes so abundant in the sea. 
Family DaPHNIDZ. 
It is noteworthy that no.species belonging to this family were obtained 
in Loch Morar at the time of our visit. 
Family BosMInip&. 
Genus Bosmina, Baird. 
Bosmina longispina, Leydig. 
1860. Bosmina longispina, Leydig. 
This species was very abundant in Loch Morar. It is readily dis- 
tinguished from Bosmina longirostris by its much greater size and by 
the larger postero-ventral spine-like processes of the carapace. 
Family Macroruricip®. 
Genus Macrothrix, Baird. 
Macrothri« laticornis (Jurine). | (Pl. VIL. figs. 28, 29.) 
1820. Monoculus laticormes, Jurine, Hist. des Mouocles, p. 151, 
Peis. fies, 6, .'7. 
1850. Macrothrix laticornis, Baird, Brit. Entom., p. 103, PI. 
DEN, digy:2. 
* C.. Beck, ay, ctt.,. p FS. 
