APPENDICULAR 1 A OF JAPANESE WATERS. 11 



The branchial cavity is narrow. The œsophagus is slightly 

 curved and opens at the middle of the dorsal side of the hirge, 

 triangular, left stomacli. The right stomach is small and is 

 connected to the upper small portion of the anterior part of the 

 left stomach {rs., figs. 9 and 11). A row of gigantic glandular 

 cells is found along the base of the left stomach (fig. 10). 

 The intestine is long and pushes the rectum anteriorly, bringing 

 it out of contact with the stomach. 



The testis is paired and rectangular in form. It covers 

 the greater part of the lateral side of alimentary canal. The 

 ovary is unpaired and lies at the back of testis. 



The tail and its musculature are both narrow. No subchordal 

 cells are present. The ratio of the greatest breadth of tail to 

 that of its musculature is 2.2 : 1, and that of length of tail to 

 its greatest breadth is 7:1. 



The largest specimen obtained was 937 /^ in length of trunk 

 and 4012 /jt in length of tail. 



3. Oikopleura niegastoma, nov. sp. 

 PL III., figs. 13-18. 



Buccal gland wanting. Eisen's oikoplast present. 

 Mouth very large; branchial cavity spaceous. Blind 

 sac of the left stomacli small and obliquely ascending 

 upward and backward; its base -widely separated from 

 the opening of œsophagus. Atrial canal wanting, 



being represented by a single external aperture of the 

 branchial cavity, situated at the j^o^'terior end of the 

 elongated endostyle. Genital glands covering the lat- 



