46 
And now as to the interpretation of this median doısal recepta- 
cle? For this we must needs bring to bear upon the question the 
results obtained by former observers as they were recapitulated at 
the beginning of this chapter. A similarly situated cavity also 
containing eggs, is mentioned by TULLBERG for Neomenia (see 
p- 36), by Hansen for Chaetoderma. TULLBERG calls it the egg- 
bag and speaks of three singular bodies partly attached to its in- 
ternal wall. Hansen calls it the pericardium and describes and 
figures how the heart is situated inside it, how the eggs enter it 
and how it ultimately communicates with the exterior in the op- 
posite direction by means of his „mucus-glands”. v. GRAFF, Ko- 
WALEWSKY and KorENn and DANIELSSEN make no mention of it, 
although the latter deseribe the heart as situated exactly in the 
position corresponding to that of TULLBER@’s egg-bag. 
My own observations on Neomenia and Proneomenia may perhaps 
serve towards clearing up this confusion. In Prof. Ray LAnkes- 
TER’S sections of the first and in my own of the latter genus I 
find that this cavity indeed contains, in addition to ova, as above 
mentioned, the heart. Also in Prof. v. GRAFF’s sections the cavity 
with the heart inside of it is found to be similarly situated, here 
however I find no eggs in the pericardial cavity. There is a gene- 
ral correspondence between the preparations and Dr. Hansen’s (7) 
figure 3, Pl. IV of Chaetoderma, and the direct homologies of the 
different portions of the apparatus concerned, cannot well be doubt- 
ed any longer. More details about the heart will be found further 
on in the description of the eirculatory system. Suflice it to say 
that ın all probability one ventriele and two auricles are present, 
identical with TULLBERG’s „three singular bodies”. 
All this affords conelusive evidence that the median cavity, pre- 
sent in all the three genera of the Solenogastres, into which 
the paired ducts of the hermaphroditic gland open out, is indeed 
the pericardium. In its turn the pericardium represents the much 
reduced body cavity, into which the genital products are thus 
discharged. They are further transported to the exterior by a system 
of duets which we are now about to describe. At the same time 
