196 K. MITSUKÜRI : STUDIES ON 



In this table, several interesting facts appear. 



1. The length of the body is commonly a little over twice 

 its breadth. In some cases, it is three times as long or even 

 longer. 



2. The number of lateral pedicels in larger individuals is less 

 than the number of the dorsal papillse. 



3. The number of lateral pedicels does not increase with the 

 size of the individuals. On the other hand, an examination of 

 various individuals shows that the lateral pedicels grow larger in 

 absolute size in older individuals. 



4. The number of dorsal papilke increases with the size of 

 the individuals. That is, older individuals have a larger number 

 of papillae than younger individuals. On the other hand, the ab- 

 solute size of the papilla3 does not increase as mucli as in the 

 case of lateral pedicels. 



Dorsal papillae are slender and conical, and in the best pre- 

 served individuals are of a considerable length, viz., 3(3 — 40 mm. 

 Some of the most anterior ones are in a transverse row. Each 

 longitudinal series may be said to be in a single line and inter- 

 nal dissection shows that they all arise on tlie median side of 

 each dorsal abulacrum. At its origin, each papilla has a not 

 very large vesicle freely projecting into the body-cavity and vio- 

 let in color. hâterai pedicels are on each side in a strictly 

 single row. Dissection shows that each pedicel has in the sub- 

 stance of the ventral perisome a cavity divided into three compart- 

 ments, which however freely communicate with one another, the 

 apparent partitions being only ridges projecting from the roof of 

 the cavity. These cavities show themselves from the outside in 

 ventral view of the animal. Tentacles 15 in number, large, disk- 

 shaped, not contractile. 



