CORRIGENDA. 
56. In the ‘‘key,’’ thirteenth line from top, read tyrrelli for tyrelli. 
73. Seventh line from top, read Herrick for He rick. 
95. Second line from bottom, read americanus for Americanus. 
101. Under Cyclops pulchellus, supply Plates X XVII, Figs. 4, 5; XXVIII, 
Figs. 5-8. 
105. Middle of page, read m. q. fuscus for m. g. fuscus. 
114. Twelfth line from top, read Cyclopina gracilis for Cyclopsina gracilis. 
120. Fourteenth line from top, read lascivus for lascious. 
124. Fourth line from bottom, read Copepoda for Copepode. 
126. Second line from top, read Cladocera for Cladocere. 
129. The last three page numbers of the ‘‘key,’’ and the last within the brackets, 
should read respectively 132, 134, 134, 135. 
146. Third line from top, read Sidide for Sidide. 
148. Third line from bottom, read Sida brachyura for Sida branchyura. 
150. Transfer the plate reference under Latona to Latona setifera. 
174. Under Ceriodaphnia cornuta, supply Plate LX VI, Figs. 4, 5. 
175. Middle of page, read Rhypophilus for Ripophilus. 
195. Eighth line from bottom, read D. kalbergensis for D. kahlbergensis. 
203. Middle of page, read cedersticemii for ccederstroemii. 
205. Thirteenth line from bottom, read D. schexfferi for D. sczehfferi. 
210. Near middle of page, read Macrothrix (?) pauper for Macrothrix (?) pauper. 
218. Read Acantholeberis curvirostris for Ancantholeberis curvi- 
rostris. 
231. Eleventh line from bottom, read Alona elongata for Alono elongata. 
255. Star Pleuroxus stramineus, Q 
258. Under Pleuroxus procurvus, add LXV, Figs. 6, 7. 
260. Under Leptorhynchus falcatus, supply Plate LXIT, Fig. 17. 
266. Under Polyphemus pediculus, read LIX for LXIX. 
272. Read Daphnia longiremis for Daphnia longiremus. 
273. Read Ilyocryptus longiremis for Ilyocryptus longiremus. 
274. Read Leydigia quadrangularis Leydig for Leydigia quadrangu- 
laris Leydig. 
274. Read Dunhevidia setiger for Dunhevidia Setiger. 
293. Fourth Jine from top, read adductor for abductor. 
301. Read Candona peireei for Candona Peircei. 
306. Read Cypria opthalmica (Jurine) for Cypria opthalmica Jurine. 
321. Tenth line from top, read Cypris gibberula for Cypris qibberala. 
Unexplained remain, Plates XXV, Fig. 15; LVII, Fig. 9; LXI, Fig. 5a; LXV, 
Fig. 9, and a few unnumbered figures. 
A number of the plate references were supplied from the explanations of plates: 
A few species are noticed only in the index and the plates. e 
I am indebted to Professors Birge avd Marsh for deciding between the conflicting 
spellings of names in the manuscript that were not observed until the index was pre- 
pared in most cases from the final forms. 
I embrace this opportunity to acknowledge the courtesy and good nature of the 
officers connected with the manufacturing department of the Pioneer Press Company, 
particularly of Mr. George R. Morrissey. 
J a 
