434 Wisconsin Academy of Sciences, Arts, and Letters. 
acteristics in direct opposition to those claimed for it by the orig¬ 
inal discoverer. 
PEOALES SIMILIS De Beauchamp. 
• Plate XVI, figures 1-5. 
Proales similis De Beauchamp, Bull. Soc. Zool. Prance, vol. 32, 1908, p. 
153, fig. 2. 
Pleurotrocha similis Von Hofsten, Zool. Bidr. Uppsala, vol. 1, 1912, p. 186; 
Harking, Bull. 81 U. S. Nat. Mus., 1913, p. 85. 
The body is elongate, slender and fusiform; its greatest width 
is one-fifth of the total length. The integument is very soft and 
flexible, and the outline is somewhat variable on account of the 
contractility of the animal. It is a very transparent species. 
The length of the head segment is very slightly greater than its 
width and a little less than the greatest width of the body. The 
abdomen is separated from the head by a slight transverse fold and 
increases slightly in width for one half its length; from this point 
it tapers gradually to the foot, ending in a minute tail, projecting 
but very slightly beyond the general outline of the body. The foot 
is relatively long, about one sixth the total length, slightly com¬ 
pressed dorso-ventrally and tapering towards the posterior end; 
it is without any joints, but is frequently wrinkled. The toes are 
moderately long, robust and conical; near mid-length they taper 
a little more rapidly and end in acute points; their length is about 
one twentieth of the total length. 
The dorsal antenna is a small setigerous papilla in the normal 
position; the lateral antennae are unusually far forward and only 
a short distance beyond mid-length of the body. 
The corona is slightly oblique and has laterally two strongly 
ciliated, auricle-like areas. The apical plate is unciliated and 
rather small; the buccal field is covered with short, closely set 
cilia. The mouth is near the ventral edge of the corona. 
The mastax is intermediate between the virgate and the malleate 
type. The fulcrum is short, broad at the base and tapers grad¬ 
ually towards the slightly fan-shaped ventral end. The rami are 
roughly triangular and have a large basal apophysis; the alulae 
are two acutely pointed cones at the external angles. No denticula- 
tions are present on the inner edges of the rami. The unci have 
each six teeth; the last two on the dorsal margin are partly fused. 
The manubria are broad and lamellar at the base, ending in a 
