208 THE SCHIZOPODA. ^ 



a. Carapace in the adults imth a denticle on or near the lower margins near 

 their posterior end. 



2. Thysanopoda tricuspidata H. Milne Edwards. 



Plate 4, fig. 2a. 



1830. Thysanopode tricuspide H. Milne Edwards, Ann. Sc. Nat., 19, p. 454, pi. 19. 



18.37. Thysanopoda tricuspidata H. Milne Edwards, Hist. Nat. Crust., 2, p. 460, pi. 26, figs. 1-6. 



1885. Thysanopoda tricuspidata G. O. Sars, Challenger Kept., 13, p. 98, pi. 17, p. 165, pi. 31, figs. 1-22 



(larval stages). 

 1910. Thysanopoda tricuspidata H. J. Hansen, Siboga-Exp., 37, p. 82, pi. 12, figs. 3a-3b. 



Sta. 4705. Dec. 28, 1904. Lat. 15° 5.3' S., long. 99° 19' W. 300 fms. to surface. 1 specimen. 



Sta. 4721. Jan. 15, 1905. Lat. 8° 7.5' S., long. 104° 10.5' W. 300 fms. to surface. 2 specimens. 



Sta. 4725. Jan. 17, 1905. Lat. 11° 38.3' S., long, 110° 5' W. Surface. 3 older larvae. 



Sta. 4728. Jan. 19, 1905. Lat. 13° 47.5' S., long. 114° 21.6' W. 300 fms. to surface. 6 specimens. 



Sta. 4729. Jan. 19, 1905. Lat. 14° 15' S., long. 11.5° 13' W. Surface. 1 very young specimen. 



Sta. 4730. Jan. 20, 1905. Lat. 15° 7' S., long. 117° 1.2' W. 300 fms. to surface. 1 specimen. 



Sta. 4734. Jan. 22, 1905. Lat. 17° 36' S., long. 122° 35.6' W. 300 fms. to surface. 2 specimens. 



Sta. 4740. Feb. 11, 1905. Lat. 9° 2.1' S., long. 123° 20.1' W. 300 fms. to surface. 1 specimen. 



To the description given by Sars and that in the "Siboga" Report some 

 remarks on the maxillulae may be added for comparison with the same organs 

 in the following forms. The lobe of first lobe, the proximal lobe (fig. 2a, 1 .) 

 is somewhat broad, with the end nearly regularly rounded; the lobe from third 

 joint (1 .) is moderately broad, not widened towards the end, about as broad as 

 the terminal part of the proximal lobe and considerably narrower than in the 

 following species; the fourth joint (4.), the palp, is comparatively large, somewhat 

 longer than the lobe of third joint, widening much from the base to beyond the 

 middle, more than half as broad as long, with the end almost cut obliquely, 

 setose both along the long and the little convex terminal margin, and on the 

 outer margin. The pseudexopod (px) is only moderately large, not larger than 

 the inner distal, transverse portion of the proximal lobe, very oblong, with 

 about its half situated outside the outer margin of the third joint and co\'ering 

 only a verj^ small part of the fourth joint. 



Distrihulion. — According to the literature (Sars, Ortmann, Hansen) and 

 to the material at hand this characteristic species is common in the tropical 

 Atlantic, ranging northwards to the Sargasso Sea (Ortmann) ; it occm's also 

 in the Indian .Ai-chipelago and adjacent areas, and it has been taken at \-arious 

 places in the tropical Pacific and even more to the southwards in that Ocean 

 (Sars). The Copenhagen Museum possesses specimens from more than thirty 

 locaHties, the majority from the Atlantic between Lat. 28° 12' N. and 22° S., 

 but eight among the Stations from the seas around Southeastern Asia, f. inst, 

 Lat. 13° S., long. 103° 20' E.; Lat. 16° 8' S., long. 111° 50' E.; Lat. 10° N., 



