ASTEROPHILA. 99 



the liver is of a light brownish shade while the other organs are 

 unpigmented and more or less translucent, especially in the case 

 "I i IK pseudopallium that in life is so thin and transparent that 

 tin- torm and movements of the larvae may be readily observed. 

 A- may be seen in PI. I., Fig. I, there are two openings into the 

 body, one the mouth, corresponding in position to the hilum of 

 ,t In -.in while the reproductive opening is placed laterally up- 

 ward- of thirty degrees. 



I nun \arious features of its organization it i- readily po-sible 

 to orient this animal and discover the axes of the body. As in 

 -ev.ral other parasitic gastropods the body is surrounded by a 

 pseudopallium that appears to be a development <>f the Miout or 

 adjacent regions of the body. Growing upward it ha- en\ eloped 

 ilir body completely save at one point, the reprodncti\e and 

 excretory pore. Considering the body proper, tin- foot i- seen 

 \i-t in the form of a small though broad wedgc--haped fold 



I'l. I . 1 ig. I. /) covered with epithelium of greater thickne-- 

 than thai surrounding the body generally. In section- I'l 11., 

 Fig. i it is a fairly conspicuous object owing to its affinity ii 

 -tain-. Again, well-defined pedal ganglia and otocysts, located 

 in lose proximity to the foot and cerebral ganglia on the oppo-ite 

 -ide of the digestive tract, demonstrate the fact that the antero 

 iior axi- is the shorter of the roughly cllip-oid bo 1\ , and 

 that the transverse axis is accordingly the longer. 



In tin- -|>ecies the degenerative processes ha\e a<l\aiurd to a 

 stage \\liere the mantle and mantle cavity ha\e largelv di-- 

 appeared, and vet. though rudimentary, they maintain tin ii 

 i\ pi. al relations. Since the mantle fold is coniparaiixely narrou 



I'l. 1.. Hg-. i. 2, t,') the cavity is accordingly -hallow, as the 

 mantle i- closely applied to the visceral mas>; ne\ . -rthele-- the 

 epithelial cells bounding the cavity are not only higher than tin >se 

 cUeuhere covering the body but they stain more inten-elv and 

 are ciliated. < Mi the left-hand side of the body the mantle bonlei 

 thicki-n- con-iderably, and forms a projecting riilge th.it cn- 

 tinues until the p.illial cavity itself di-appeai>. In the -malle-t 

 specimen the mantle and cavity are relatively larger and the 

 mantle fold is much more glandular, the gland cell- being large 

 and conspicuous 



