662 REPORT OF COMMISSIONER OF J^ISH AND FISHERIES. 



of those which really prey upon our common fishes. The species are 

 usually not conspicuous, and are very likely to be overlooked by or- 

 dinary observers. The Lernteans, which include the commonest and by 

 far the most injurious species, may be attached to any part of the fish^ 

 and should be specially looked for upon the gills and about the gill- 

 openings and throat. It is important that specimens should be collected 

 in large numbers for study. For this purpose, they should be preserved, 

 while quite fresh, in small bottles of alcohol or other strong spirit. 



Family Argulid^. 



Argulus Catostomi Dana and Herrick. 



American Journal of Science, Ist series, vol. xxx, p. 383, 1836, and vol. xxxi, p. 297, 

 plate, 1837. 



Parasitic on the " sucker," a species of Catostomus, in Mill River, near 

 New Haven, Conn., in both fresh and brackish water. 



Argulus FuuduU Kroyer, (Bidrag til Kundskab om Snyltekrebsene, 

 p. 20, pi. 2, fig. 1, 1863,) should, perhaps, be included in this list, as it is 

 described as found upon Fundulus limbatus Kroyer, from ISTew Orleans, 

 but it is not stated whether from salt or fresh water. 



Family Caligid^. 

 Lepeophtheirus Salmonis Kroyer. 



Caligus Salmonis Kroyer, Naturhistorisk Ticlsskrift, vol. i, p. 622, 1837, vol. ii p. 



13, 18, pi. 6, fig. 7, 1838; Edwards, Hist. Nat. des Crustacds, vol. iii, p. 455 ; 



Steenstrup and Liitken, Bidrag til Kundskab om det aabne Havs Suyltekrebs 



eg Lernteer, p. 15, 1861. 

 Caligus i-es2>a Edwards, op. cit., vol. iii, p. 456, 



Lepeoptheir us Stroma Baird, Britisli Entoraostraca, p. 274, pi. 32, figs. 8, 9, 1850. 

 Lepeophtheirus Salmonis Kroyer, Bidrag til Kundskab om Suyltekrebsene, p. 137, 



p]. 17, fig. 1, in Naturhistorisk Tidsskrift, III, vol. ii, 1863. 



Parasitic on the salmon of our eastern coast and of Europe. It is 

 perhaps more properly a marine than a fresh- water species, but is car- 

 ried by the salmon far up the fresh water rivers. 



Ergasilus Funduli Kroyer, (Bidrag til Kundskab om Snyltekrebsene, 

 pp. 2li8, 238, pi. 11, fig. I, 18(33,) from Fundulus limbatus Kroyer, from 

 New Orleans, is perhaps to be added to this list. 



Family Lern^opodid^. 



ACHTHERES PiMELODi Kroyer. 



Bidrag til Kundskab oin Suyltekrebsene, pp. 272, 275, iil. 17, fig. 5, 1863. 



Upon a specimen of Plnelodiis maGulatus, from Cincintiati, according 

 to Kroyer, from whose work I translate the following diagnosis : "Arms, 

 by which the aniuial is attached, much longer than the head, slender, 

 nearly straight ; bulla (tiie extremity of the uuited arms) very small, 

 sessile. Body annulated into five seguients, and uiarked with two dor- 

 sal, longitudinal sulcatious. External ovaries equa ling or exceeding the 



