MR, E. J. MIEES OjS' THE IDOTEIDJi. 37 



pelagic species, occurring probably everywhere, except in Arctic 

 and Antarctic latitudes. Specimens from the open sea, but 

 without indication of locality, are iu the Museum collection, 

 obtained during the voyages of H.M.SS. ' Herald ' and ' Eattle- 

 snake,' &c. ; three males and two females in spirit from the N. 

 Atlantic, lat. 55° 49' N., long. 16° 44' W. ('Valorous' Exped., as 

 I. rohusta) ; from the N. Atlantic, lat. 20" N., long. 22° 53' W., 

 an adult male and four smaller specimens, and lat. 31° 30' N., 

 long. 23° 0' W., an adult male, female with ova, and young, both 

 obtained from the towing-net and preserved in spirit ; a young 

 example, in spirit, from the Mediterranean ; an adult male and 

 two females, in spirit, from the Atlantic (Capt. J. B. Grodfrey) ; 

 two males, in spirit, from Vineyard Sound, Massachusetts (U.S. 

 Fish Commiss., as /. rolusfa) ; a male and two females from "W. 

 Africa (Bewsher) ; a series of specimens from the South Atlantic, 

 lat. 34° 43' S., long. 4° W., and lat. 35° 21' S., long. 35° 22' W., 

 preserved dry, and collected by J. MacGillivray (H.M.S./Eattle- 

 snake'); several specimens, in spirit, collected between Monte 

 Video and the Straits of Magellan (Dr. E. 0. Cunningham, 

 as I. annulatd) ; a series of specimens, in spirit, from the 

 S. Pacific, lat. 25° 18' S., long. 178° 54' W. (H.M.S. ' Herald,' as 

 I. pelagica); three specimens (preserved dry) from Cape Byron, 

 N. S. Wales (collected by J. MacGillivray, H.M.S. ' Eattle- 

 snake '), and one, dry, from Bdrneo (Admiralty), designated by 

 White as /. compacta', besides others, whose locality has either 

 never been recorded or has been lost. 



It is remarkable that no specimen should (so far as I am aware) 

 have as yet been recorded from the British coasts. 



I have observed considerable variation in the degree of promi- 

 nence of the epimera and in the width of the thoracic segments. 

 In some, even adult, examples the epimera do not project at 

 all, and the serrated appearance of the sides of the thorax is lost. 

 The younger individuals are generally narrower, with the sides 

 more nearly parallel. 



I think that the I. peloponesiaca of Eoiix is to be referred to 

 this species rather than to I. emarginafa, where M. Eoux and 

 S. Bate and Westwood place it, on account of the prominent eyes, 

 serrated lateral margins of the thorax, and the coloration. The 

 terminal segment is described as convex and truncated, although 

 represented as slightly emarginated. Griierin, Exp. de Moree, Cr. 

 p. 49 (1832), adds no information about this species. 



