Some Notes on Alcippe lampas (Hasc.). 193 
contraction with the group of protrusors the antagonistic retractors 
bring about the rhythmical play which we observe. 
The third group of muscles are those of the body itself: the 
Dilatatores and Constrictores oesophagi, the muscles of the mouth- 
parts, of the different regions of the stomach and body wall, of the 
oral cirri and finally those which pass into and those which are 
within the terminal cirri. With the exception of the cirri muscles 
an attempt was made to show in Fig. 8, 16, and 12 as many as 
could be worked out. They can be understood by a glance at the 
diagrams. The oesophageal muscles have, moreover, been described 
and figured by BERNDT. 
There seem to be present two kinds of muscles, those with a 
very fine. sometimes hardly visible striation, and those with very 
distinct and coarse markings. To the former type belong those 
which connect the body and the disk and those which are found 
in the caudal portion of the animal, while the muscles around the 
oesophagus and stomach belong to the second type. 
The digestive apparatus. 
The mouthparts have been described and figured by several 
authors. Since I find a number of differences from Hanxcock’s and 
Darwın’s drawings as well as from Auvrtvituius’, it was thought 
advisable to publish my sketches. Some future author may find 
them .useful, esp. if he wants to compare again the European and 
the American form. 
There is no labrum present (Fig. 12). The upper edge of the 
mouth serves as upper lip. 
On each side of the mouth projects a little soft flap or lobe, 
the “palp” of Aurtvintius. In Fig. 13 the position of this palp 
with reference to the entrance into the oesophagus is seen, while 
Fig. 12 and 14 bring out the two palps and their relation to the 
other mouthparts. 
The mandible is the largest and strongest of the mouthparts. 
Its form is that of a somewhat bent flat plate terminating into a 
strong tooth. It differs in my specimens a little from the drawings 
of the authors. The flat surface is placed sagittally to a certain 
extent, so that in a side view of the mouth the mandible appears 
almost fully (Fig. 13 and 14), while in the ventral view of the 
mouth (Fig. 12) its sharp cutting edge is seen projecting and the 
Zool. Jahrb. XXI. Abt. f. Anat. 13 
