New Turbellarian Associate of Hermit Crab — Prudhoe 
411 
but figures of them, in which are shown the 
number and arrangement of the cerebral eyes, 
as well as the elongate contour of the seminal 
vesicle, suggest that the worms are, in these 
features, more comparable with the present form 
than with the type specimen of E. opisthoporus. 
It seems possible, therefore, that only one 
species of Emprosthopharynx inhabits the 
"houses” of pagurids in the eastern Pacific, and 
that it is different from the free-living form 
occurring in the Galapagos. 
REFERENCES 
Bock, Sixteen. 1913. Studien liber Polycladen. 
Zool. Bidrag. Uppsala 2:29-344, 8 pis. 
1925. Papers from Dr. Th. Mortensen’s 
Pacific Expedition 1914-16. xxv. Planarians. 
Parts I— III. Vidensk. Medd. Dansk. naturh. 
Foren. 79:1-84, 22 figs., 4 pis. 
1931. Die Polycladen. Deutschen Siid- 
polar Expedition 1901-03. Vol. 20 (Zook): 
259-304, 23 figs., 4 pis. 
