MINUTE ANATOMY OF MEDITERRANEAN NEMERTEANS. 253 
Digestive and Circulatory System. 
In accordance with Mr. MacIntosh’s statements I found the 
mouth in the Enopla situated Jefore the ganglia, ventrally, a 
little behind the opening for the proboscis. In Meckelia soma- 
totomus the ciliated wsophagus is distinct from the subse- 
quent part of the digestive cavity in which the cecal ap- 
pendages appear. ‘The cesuphagus is further provided with 
very thick glandular walls. In Drephanophorus it is, on the 
contrary, very short, provided with thick glandular walls even 
before the ganglia, whilst the regular ceecal appendages make 
their appearance at no great distance behind these. 
The circulatory system in Drepanophorus shows many 
points of resemblance with the same apparatus in Borlasia 
splendida (Amphiporus spectabilis, McInt.) as described 
by Keferstein. Besides the three longitudinal vessels a 
great number of anastomotic vessels, perpendicular to the 
first, occur, one in each interceecal space. The contained 
fluid carries numerous red blood-corpuscles, which proved 
upon examination with the spectroscope to owe their colour- 
ing to hemoglobin. This fact was already ascertained for 
Polia sanguirubra by Mr. Ray Lankester.' 
For the larger Borlasian forms, such as Meckelia soma- 
totomus (Leuck.), Polia geniculata (Delle Ch.), whose dark 
pigmentation prevents their being studied under compression, 
I could ascertain in longitudinal sections that here two fine 
anastomotic vessels—one for every intercoccal space—unite 
the dorsal vessel with the two lateral ones. 
As to Meckelia somatotomus (Leuck.), Cerebratulus margi- 
natus (Kef.), my observations confirm those of Mr. MacIntosh, 
who found in this species the vessels in their ordinary place, 
close to the nerve-trunks, thus contradicting Keferstein’s 
statements on this point. I cannot, however, agree with Mr. 
MacIntosh in regarding the position of these blood-vessels 
in the Borlasians as quite constant. Polia geniculata, for 
example, carries its lateral vessels nearly in the middle of the 
body cavity, suspended by connective tissue under the intes- 
tine. 
Nervous System. 
The difference which exists between Enopla and Anopla in 
respect to shape and position of the ganglia and nerve-trunks 
was already pointed out by preceding investigators, and 
‘clearly stated by Mr. MacIntosh. A corresponding differ- 
1 © Proceedings of the Royal Society,’ No. 140, 1873. 
