22 AKT. 5. T. AIDA. 



epithelial cells of the lateral oikoplast zoue are of various shapes 

 and take a characteristic arrangement (fig. 1(3, PL IV.). The 

 endostyle is short and widely sejmrated from the anus and atrial 

 canal. 



The œsophagus is short and opens into the connection between 

 the two lobes of stomach. The left stomach is large and triangular 

 in shape, entirely encircled by a row of gigantic glandular 

 cells {Is., fig. 16, PI. IV.). The right stomach is smaller 

 and of a rectangular shape ; it has the row of glandular cells at 

 the anterior margin (rs., fig. 12, PI. IV.). The intestine is long 

 and large, makes a right angle with the right stomach and opens 

 at the posterior end of rectum on the right side. 



The reproductive gland, in its early stage, is represented by a 

 small patch between the two lobes of stomach. In later stages, 

 it extends both anteriorly and posteriorly, and assumes a narrow 

 ribbon-like form (fig. 14, Pi. lY.). After reaching its full 

 length, the organ is broadest at its dorsal and ventral ends, and 

 completely covers the alimentary canal on the upper and lower 

 sides, so that this can not now be traced without dissecting 

 (fig. 13, PI. IV.). 



The tail has a narrow muscular coatin";. It has manv sub- 

 chordal cells on the right side of the chorda, arranged in a single 

 row with regular intervals. In all my specimens I have found 

 a group of peculiar Hat cells at the top of tail on both the dorsal 

 and ventral surfaces, (fig. 15, PI. 1\".). The ratio of the length 

 of tail to its greatest breadth is 5,5 : 1 ; that of the greatest 

 breadth of tail to the width of its muscle, 2,1 : 1. 



The specimen with the genital gland in the most advanced 

 state of development has trunk-length of 1388 /u and tail-length 

 of 5111 /-«. One specimen which had lost the anterior half of its 



