AN I0HTF1Y0BDELLJD PARASITLC ON SAND WRITING. 25 
genus Pontobdella, has a single large undivided blind 
pouch. The third type, to which all remaining genera belong, 
shows transition forms between these two types. They have 
blind pouches fused for a greater or less extent in five places. 
In this group he placed the genera Platybdella, Piscicola, 
Cy st obranchus, and Callob della, and by the researches 
of Sukatschoff (1912) Branchellion must be included along 
now with Austrobdella. The development of the structure 
of the blind gut seen in the second and third types Johansson 
correlated with the fact that the leeches possessing it are 
enabled to exist for some time away from a host by reason of 
the greater storage capacity produced by this partial or com- 
plete fusion : and with the fact that it is found along with 
well-develoded musculature indicating good swimming power 
in such genera as are likely to experience difficulty in finding 
a fresh host. To this likely hypothesis as to the cause of the 
development of this fusion of the blind pouches Austrobdella 
affords little support. In fact, the case presented here is almost 
as hard to fit in with Johansson's hypothesis as that ofCallob- 
della lophii, to explain which Johansson (1898) has to say 
that ec it is hardly too bold to think that this leech never leaves 
its host." He offers no explanation as to how the cocoons 
are deposited, though elsewhere he states that all Ichthyob- 
dellids, so far as is known, deposit their cocoons away from 
their hosts. Here I may mention a note by Leigh- Sharpe 
(1913) about the capture of a large angler (Lophius 
piscatorius), only a few hundred yards from shore, with five 
.specimens of C. lophii. Nowin Austrobdella the blind 
gut is better developed than in C. lophii; the musculature 
is weak (about the same as C. lophii), and the ability to 
swim absent. The sand whiting, on which Austrobdella is 
exclusively parasitic, so far as I can ascertain, is common, and 
lives in very shallow water and feeds along shoals and beaches, 
frequently burrowing in the sand. According to this mode of 
life, following the reason used by Johansson for Ab ranch us, 
there should be little need for extra storage of food, yet in 
Austrobdella I find a development of the blind gut about 
