^^OL- 3] Kofoid. — Triposolenia. 109 



The midbody is long and narrow, its dorso-ventral diameter 

 taken midway of its length, being 0.4 of its axial length. Its 

 dorsal and ventral margins are siibparallel, tapering but little 

 posteriorly. The antapex is bluntly rounded, being almost trun- 

 cate. The length of the midbody equals that of the head and 

 neck, equals the distance from its antapex dorsally to the dorsal 

 horn, is a little more than the corresponding distance to the ven- 

 tral horn and is somewhat less than 0.25 of the total length. The 

 anterior process extending from the midbody to the flagellar pore 

 has the usual size and proportions. The neck is nearly parallel 

 to the general trend of the antapicals and the long axis of the 

 midbody, being bent dorsally in a gentle curve about 12° from 

 a parallel to the axis. The head is spheroidal with a convex 

 epitheca. 



The antapicals arise as in T. t-amiciformis, but begin at once 

 to curve posteriorly in an arc which brings them to an antero- 

 posterior direction within the length of the midbody, thus nearly 

 obliterating the localized major flexure seen in T. ramiciformis. 

 The sigmoid posterior curvature of the antapicals is freely devel- 

 oped. The tips are rounded, without spinules. There are 2-3 

 feebly developed tubercles on the dorsal and ventral margins re- 

 spectively of the dorsal and ventral horns within the level of the 

 midbody. The lateral curvature in the antapicals has not as yet 

 been determined. The length of the dorsal and ventral horns is 

 2.1 and 2.3 times the axial length of the midbody respectively. 

 The inequality in the antapicals is greater than in any other 

 species here described. The distance between the antapicals at 

 the level of the antapex of the midbody and at the tips are re- 

 spectively 1.8 and 1.6 times the axial length of the midbody. 



The thecal wall is hyaline and not pitted nor reticulate. The 

 transverse lists are faintly and sparingly ribbed and the longi- 

 tudinal ones are without structural differentiation. A faint su- 

 ture spine is located posterior to the flagellar pore. 



Dimensions : Length, 165 /x ; altitude of midbody, 45 /x ; 

 length of anterior process, 61 fi; length of antapical horns, 94 

 and 103 fx. 



Taken in vertical haul from 100 fathoms off San Diego in 

 July. 



