JOURNAL OF MICROSCOPICAL SCIENCE. 
DESCRIPTION OF PLATE [a, 
Illustrating the Rev. W. Houghton’s note on Canals in the 
Head of the Hel. 
Fig. 
1.—Head of A. acutirostris, showing the orifices of the canals. 
a, Anterior orifice. 
6. Posterior ditto. 
2.—The same, with the soft parts removed, and with a bristle inserted 
into each canal. 
3.—Side view of same. 
4.—Vertical section of cranium of 4. acutirostris. 
5.—Membranous fold or hollow in which the canal terminates. 
