202 
H. L. JI. PIXELL. 
one third from oral end, they have the pinnate arriingeinent 
found in Ph. psammophila (Cori [3]), architecta (Andrews 
[1]), pacifica (Torrey [15]), i. e. the fascicles appear feather- 
hke in transverse section. 
Text-fig. 3. 
Transverse section thronijh the pregastric region to show the 
high pinnate character of the fascicles of longitudinal muscles. 
(X 150.) 
Frequently there are 19 of these in the left anterior cavit}', 
22 in the right anterior, 13 in the right posterior and / in 
the left posterior, or according to Selys Longchainps^ con- 
venient formula — 
19 ' 22 
= 61 as in tig. 2. 
7 13 
