364 



BULLETIN 54, UNITED STATES NATIONAL MUSEUM. 



IDOTHEA BALTICA (Pallas). a 



Oniscus balticus PALLAS, Spic. Zool. (9), 1772, pp. 67-68, pi. iv, fig. 6. 

 Idolea entomon PENNANT, British Zool., IV, 1877, p. 25, pi. xvm, fig. 5. 

 Stenosoma irrorata SAY, Journ. Acad. Nat. Sci. Phila., I, 1818, p. 423. 

 Idotea tricuspidata DESMAREST, Diet, des Sci. Nat., XXVIII, 1823, p. 373, pi. XLVI, 

 fig. 11; Consid. Crust, 1825, p. 289, pi. XLVI, fig. 11. Roux, Cr. de la Medi- 

 terrane"e, 1828, pi. xxtx, figs. 11, 12. GOULD, Rep. Geol. Mass.,2d ed., 1835, 

 p. 549. MILNE EDWARDS, Hist. Nat. Crust., Ill, 1840, p. 129. 

 Idotea irrorata MILNE EDWARDS, Hist. Nat. Crust., HI, 1840, p. 132. 

 Stenosoma irrorata GOULD, Rep. Invert. Massachusetts, 1841, p. 338. DE KAY, 

 Zool. New York Fauna, Crust., Pt. 6, 1844, p. 43, pi. x, fig. 42. 



Idotea irrorata STIMPSON, Smithsonian Contribu- 

 tions to Knowledge, VI, 1853, p. 39. LEIDY, 

 Journ. Acad. Nat. Sci. Phila., 1855, p. 150. 

 Idotea tricuspidata SARS, Forh. Vidensk. Selsk. 

 Christ., 1859, p. 151. NORMAN, Report British 

 Assoc., 1868, p. 197. BATE and WESTWOOD, 

 British Sessile-eyed Crust., II, 1868, p. 379. 

 Idotea irrorata HARGER with VERRILL, Report U. S. 

 Fish Comm., 1873, Pt. 1, p. 569, pi. v, fig. 23; 

 p. 316. VERRILL, Am. Journ. Sci. Arts (3), 

 VII, 1874, pp. 131, 134; Proc. Amer. Assoc., 

 1874, pp. 369, 371, 373. WHITEAVES, Am. 

 Journ. Sci. Arts (3), VII, 1874, p. 217. 

 Idotea triaispidata STEERING, Journ. Linn. Sue. 



London, Zool., XII, 1874, p. 148. 

 Idotea irrorata HARGER, Proc. U. S. Nat. Mus., II, 

 1879, p. 160; Report U. S. Fish Comm., Pt. 

 6, 1880, p. 343, pi. v, figs. 24-26. 

 Idolea marina MIERS, Journ. Linn. Soc. London, 

 Zool., XVI, 1883, pp. 25-31. RICHARDSON, 

 Proc. U. S. Nat. Mus., XXIII, 1901, p. 540. 

 Idotea tricuspidata DOLLFUS, Feuillesdes jeunes Na- 

 turalistes, 24th year 1893-1895, p. 55. 

 Idotea baltica SARS, Crust. Norway, II, 1899, pp. 80-81, pi. xxxn. NORMAN, Ann. 



Mag. Nat. Hist. (7), XIV, 1904, pp. 441-442. 

 Idotea marina PAULMIER, Bull. New York State Museum, 1905, pp. 175-176. 



Localities. Atlantic coast from Nova Scotia and Gulf of St. Law- 

 rence to North Carolina; Bermudas; Barbados; also Mediterranean, 

 Black, and Caspian seas; west coast of Europe to Great Britain; 

 shores of the Netherlands; in German Ocean and Baltic Sea; Bohus- 

 lan, Sweden (W. Sachs); RunmarO, Stockholms skargard (J. Lindahl); 

 on Scandinavian and Finland coasts; South America, at Desterro and 

 Rio Janeiro, Brazil; New Zealand; Red Sea; Java. 



Found on surface, on floating seaweed, among algae and eelgrass, 

 in sand and gravel; from stomach of smelt, Osmerus mordax. 



Depth. Surface to 119 fathoms. 



I have accepted the name adopted by Sars for this form, Oniscus marinus Lin- 

 naeus being more properly applied to a species belonging to the genus Jsera, as Sars 

 has suggested. Although Oniscus tridens Scopoli is earlier than Oniscus balticus, it 

 probably refers to another species of Idothea, as Dollfus has pointed out. 



FIG. 3W. IDOTHEA BALTICA 

 (AFTER HARGER). x 2. 



