



Dimensión Nu.- length "t" the column was 2.0 2.5 min. and its diameter al the 



margin was about the same. 



olour. rhe column and oral disc had a faint brownish tinge and the tentacles 



were a deeper shade "t" the same colour. 



Structure. - rhe genera! arrangement <>t" the mesenteries is shown in the text-figure 

 VII, which represents a plan of one <<( the specimens reconstructed from serial sections '). rhe 

 have, however, been added from another individual, since in the one selected 

 mstruction they could not be clearly identified. 



The siphonoglyph is but feebly marked and is not prolonged aborally, although the 



directive mesenteries extend some distance below its lower border 

 The second protocnemes, counting laterally from the directives, 

 are provided with mesenterial filaments throughout nearly their 

 entire length, the filament being of the trefoil form down to a 

 short distance above its termination. These mesenteries are also 

 the longest and just above their termination each bears an acontium. 

 This combination of characters distinguishes them from all the 

 other mesenteries and clearly marks them as the telocnemes. 



The two remaining protocnemes are similar to ene another 

 in structure, the third being somewhat shorter than the fourth. 

 Each possesses a relatively Ion- trefoil filament, that of the fourth 

 being the longer, and this is succeeded by a well marked branching 

 region. below which the filament disappears. Neither ol these 

 mesenteries bears acontia. 



I M deuterocnemes there are present on one side five and 



on the other si.\, the most dorsal mesentery on each side being 



quite small and hardly projecting beyond the lower border of the stomatodaeum. Among the 



two varieties may be recognized, in one of which the trefoil portion ot the mesentery is 



much shorter than in the other, so that the branching portion begins at a much higher level 



and there is a longer stretch of it devoid of a filament. It seems proper to regard the 



of this variety as identical with the brachyenemes of the adult forms and those 



of the other variety as corresponding to macrocnemes, and since the two varieties alternate, 



is an indication of the quartette arrangement, the formula for the completed quartettes 



being B M /> »i. 



No reproductive organs occurred on any of the mesenteries. The state oi preservation 

 of tl Lamined did not permit of any study "f the minuter histological details, but it 



may be stated that the mesogloea is throughout rather thin and exceedingly so in the mesenteries, 

 a condition very different from that described by van Beneden for Apiactis denticulata. 



vu. 



run showing the arrangement 

 of the nu mt tentacle 



1:1, of larval form irtions are arbitntry, while 



drawn to scale, the object beiog i<> reprcsenl thi lengths "I the parts. 11" 



heavy lin earing the n esents the 



! tlie filan 



32 



