CRUSTACEA. 
343 
Suborder OladOcera. 
1st division. Calyptomera^ with dorsal valves and nervous system in a 
ganglionic chain. 
Tribe 1. Ctenopoda : 6 pereiopoda alike, foliaceous, pectinated, having 
branchial lamingie attached to all. 
Families Sididce and Ilolopedidce. 
. Tribe 2. Anomopopa : pereiopoda dissimilar, anterior more or less pre- 
hensile, destitute of branchial laminaj ; second pair of antennje biramose. 
Families Daphniidoi, Bosminidce, Lyncodaphnidce, Lynceidce. 
2nd division. Gymnomera : without valves ; nervous system united into 
one ganglion. 
Tribe 3. Onychopoda : pereiopoda naked, subcylindrical, four pairs 
armed with a strong unguis. Branchial laminae small and rudimentary. 
Family Polyphemidce. 
Tribe 4. Haplopopa : pereiopoda naked, simple, subcylindrical. 
Family Leptodoridm. 
The present memoir treats of the first two families only ; of 
these the Sidid(2 have four genera, which the author arranges 
according to the following table : — 
Superior ramus of the second pair of antennas triarticulated. 
Cephalon rostrated. Pleon armed Cephalon without rostrum. Pleon 
with a row of strong spines on the not armed with posterior dorsal 
posterior dorsal surface. spines. 
Sida. Limnosida (g. n., p. 36). 
Superior ramus of second pair of antennae biarticulated. 
Cephalon long, narrow, without Cephalon broad, large. Posterior ^ 
rostrum. Posterior dorsal surface dorsal surface of pleon armed with a 
of pleon destitute of spines. few spines. 
Daplmella, Latona, 
Fam. SiPiPiE, Sars. 
Sida crystallina (Muller), Sars, 1. c. p. 33, tab. 1. figs. 1-16; S. elongata (De 
Geer), Sars, 1. c. p. 35, tab. 1. figs. 18-32, near Christiania. 
Lwinosida frontosa, sp. n., Sars, 1. c. p. 37, South Norway. 
Daplmella hrachyiira (Lieven), Sars, 1. c. p. 44, tab. ii. figs. 16-24; D. 
hrandtiana (Fischer), Sars, 1. c. p. 45, tab. ii. figs. 25-33. 
Latona setifera (Fr. Muller), Sars, 1. c. p. 47, tab. iii. 
Fam. IIoLOPEDiPiE, Sars. 
Ilotopedium gihherum (Zaddach). Sars, 1. c. p. 67, tab. iv., has fully de- 
scribed the genus as well as the species. 
PoLYPHEMID^. 
Dvadne nordmanni (Loven), G. Brady, Intellectual Observer, vol. vii. p. 4, 
pi. i., and Nat. Hist. Trans, of North. & Durham, p. 30, off Tynemouth ; E. 
polypliemoides (Leuckart), G. Brady, Intellectual Observer, vol. vii. p. 4, which 
the author describes fully, as well as Dana’s genus Pkopcs as defined by 
G. O. Sars, under the*name of Pleopes polyphetnoides (Leuckart), Nat. Hist. 
