160 BRODE. [VoL. XIV. 
(b). Comparative. 
Oligochaetes. — In this discussion of the sense organs in the 
various forms I shall confine my attention to those organs which 
are distributed over the surface of the body, generally termed 
“touch organs,’ and which are diffusely or metamerically 
arranged. 
Vejdovsky } summarizes the discoveries made prior to 1884, 
and classifies the various forms of ‘touch organs” as touch 
papillae (“Tast papillen ’’), touch. hillocks (‘ Tasthiigel”’), and 
cup-shaped organs (‘‘becherformigen Organen”’). The “touch 
papillae’ are organs similar to those found in Chaetogaster. 
The “touch hillocks”’ are non-retractile elevations such as are 
found on WVazs appendiculata. The “cup-shaped organs’”’ have 
been described in Lumbriculidae and Lumbricidae. 
These organs which Vejdovsky has classed in three groups 
are much alike. ‘Touch papillae” and the “cup-shaped 
organs’’ seem to be names applied to organs both of which 
may appear either as papillae or as insinkings of the skin. 
They are essentially identical in structure. The “touch hil- 
locks ” differ from the other organs in that they are not retrac- 
tile. They usually occur in forms which have a covering of 
débris over the surface of the body. The sense organs project 
through this covering. 
Miss Randolph? has described organs in some Tubificidae 
which she considers intermediate between the “touch papillae ”’ 
and the “touch hillocks.’’ Bousfield® considered that the 
genus Ophidonais should be united with that of Slavina on the 
ground of similarity of sense organs. In reply to this, Stolc4 
asserts that the organs of Ophidonais differ much from those of 
Slavina, the former being “touch papillae,” while the latter are 
“touch hillocks.” However, it can hardly be said that they 
1 Vejdovsky, Z.c., pp. 96-99. 
2 Harriet Randolph, Beitrag zur Kenntnis der Tubificiden, Jenatsche Zeit. f. 
Naturg., Bd. XX VII, N.F. XX, p. 465. 
3 E. C. Bousfield, Slavina and Ophidonais, Jour. Linn. Soc., XIX; Jour. Royal 
Mic. Soc., 1886, p. 445. 
+ A. Stolc, Beitrage zur Kenntnis der Naidomorpha, Zool. Anz., Bd. IX, 1880, 
P- 503- 
