MYSIDACEAN CRUSTACEANS TATTERSALL 539 



A specimen in the collection from station 4101 and labelled L. inter- 

 medins resembles other specimens from this station so closely in all 

 respects that it should be referred with them to L. haivaiensis. 

 Most of the specimens in the collection are juvenile, but in those 

 sufficiently mature for their sex to be ascertained, the rostrum is 

 not invariably longer in the females than in the males. Possibly, 

 this character develops only with maturity. 



Lophogaster schmidti Fage 



FlGHBE 5 



Lophogaster schmidti Fage, 1910, p. 324; 1042, p. 34, figs.— O. S. Tattersall, 1955 

 pp. 44^45, figs. 



Occurrence: Station 3: cruise 32 of U.S. Fish and Wildlife Re- 

 search Vessel Hugh M. Smith, 21°0' N., 157°54' W., Feb. 2, 1956 

 (night); Isaac-Kidd trawl, oblique haul approximately 500 m., 1 

 immature 9, 10 mm. Station 9: cruise 30 of R/V Hugh M. Smith, 

 26°09' N., 167°17' W., Aug. 19, 1955 (night); Isaac-Kidd trawl, 

 oblique haul approximately 550 m., 2 adult d\ 20-25 mm., 1 imma- 

 ture d\ 18.5 mm (damaged), 1 ovigerous 9, 15.5 mm., 2 immature 

 9, 14 and 15 mm. 



Remarks: These specimens agree remarkably closely with the 

 published descriptions and figures of L. schmidti as follows: 



The integument is quite smooth with no trace of spinulcs. 



The rostral plate is rather narrow with the central spine long and 

 slender; it extends in the males beyond the anterior margin of the 

 antcnnular lamina and in the females to the level of the distal tips 

 of the antennal scale (fig. 5a). 



The eyes are comparatively small and are almost covered by the 

 rostral plate in dorsal view exactly as in Fage's figure (fig. 5a). 



The antennal scale is exactly similar in shape and proportions, 

 but on the whole there are fewer teeth on the outer margin. One 

 adult male and the ovigerous female had three-three and three-four 

 respectivel}*; one male had four-four; two immature females had 

 four-five; and the small female from station 3 had five on one scale 

 and six on the other. This character is evidently variable (fig. 5c.) 



The profile of the dorsal margins of the "wings" of the carapace 

 is evenly concave; the alar spines are long and slender and only 

 slightly, if at all, directed upward (fig. 5d). 



The tergal spines of the last abdominal somite are unusuallv long 

 (fig. 56). 



The telson is long and narrow, nearly five times as long as its 

 greatest width. Each lateral margin bears three extremely small 

 spines in addition to the subapical spines that are themselves very 



