146 



H. B. TORREY. 



to the experimenter in this species, owing largely to the slight 

 degree to which the nematophore projects, and the narrow range 

 of its variation in length, in fractions of a millimeter, as compared 

 with the fluctuations in width of the hydrothecae. There is no 

 doubt, however, that the nematophore tends to vary, as in A. 

 octocarpa, with the growth of the hydrocladium, its maximum 

 length lying in the middle region of the latter. 



Table V. 



Measurements in mm. X9S- 



The obliqueness of the openings of the hydrothecse is recorded 

 in Table VI., in degrees of angular distance, as for A. octocm'pa, 

 with this exception, that the line defining the obliqueness is 

 drawn tangent to the depressions between the mesial and first 

 lateral, and the third and fourth laterals (the margin having but 

 nine teeth). This is a more stable standard, but could not be 

 utilized in A. octocarpa, owing to the shape of the hydrotheca in 

 that species. 



With slight irregularities, the chief among them being connected 

 with the variability of hydrotheca no. i, the obliqueness dimin- 

 ishes toward the distal end of each hydrocladium. 



