244 
dark, and is therefore probably what Uljanin described as “masses of 
black pigment”. The surface is covered with cilia, and the extremely 
thick integument contains sline glands. The frontal gland is highly 
developed surrounding brain and statocyst. Eyes are lacking, 
The mouth opening lies on the ventral surface immediately behind 
the frontal gland. It opens into a pharynx the walls of which are com- 
posed of muscle. This peculiar pharynx is indicated in the plates of 
Pereyaslawzewa. The discussion of this organ is reserved for a later 
paper. 
Fig. 3. Diagram of sagittal section of Aphanostoma pulchella (Uljanin) with f.gl, frontal 
gland; sh.gl, slime glands; «nt, integument; ov, ovaries; #, testes; p, penis; a.f, an- 
trum femininum; bs, bursa seminalis; mo, mouth; ph, pharynx. 
The reproductive orifices are situated close together on the ventral 
surface in the posterior half of the body (fig. 3° and ©). The antrum 
femininum opens into a simple saclike bursa seminalis. The ovaries are 
on each side near the ventral surface, and extend forward to the level of 
the frontal gland. The penis is a compact organ surrounded by a thick 
muscular wall. The testes are follicular occupying the space dorsal to 
the ovaries. 
In general the Neapolitan form resembles that found by Uljanin 
with the exception of the black pigment and the oblique rows of rhab- 
dites, which I have not observed. It differs from the Aphanostoma 
pulchella of Pereyaslawzewa in color, pigment stripes, and in the: 
structure of the pharynx. We must conclude, therefore, that the form 
from the Black Sea is a closely related variety. | 
Other Acoela found at Naples in February and March are 
Aphanostoma diversicolor, Otocelis rubropunctata, Convoluta hipparchia 
and Amphiscolops cinereus. 
