23 
v. GRAFF’s account of the anatomy of Chaetoderma has since 
been differently interpreted and another deseription of the genital 
apparatus drawn up by G. A. Hansen (7). This naturalist who 
disposed of a far richer material, was thereby enabled to correct 
different statements and to give us a more complete insight into 
the anatomy of these animals. He shows that v. GraArr’s yolk- 
secreting apparatus is a widened portion of the intestine which ends 
blindly (liver), whereas the intestine itself, preserving its ciliated 
coating, proceeds backwards with a considerably reduced lumen. 
v. GrArr’s oviduct is shown to be a dorsal blood-vessel and the 
germinal vesieles of which v. GrRAFF describes the formation in the 
anterior connective tissue are regarded by Hansen as being ele- 
ments of the blood or of the connective tissue. 
Further Hanse describes the sexes of Chaetoderma as being separa- 
ted and the genital gland situated dorsally in the posterior part of the 
body. The dorsal bloodvessel accompanies it and it is divided into 
compartments by folds of the surrounding connective tissue. The ova 
are not provided with a membrane and are found in very different 
stages of development, but an epithelium from which they might 
take their origin, could not be detected by Hansen. The elements 
of the testes were equally noticed. 
Lastly Hansen gives a description of two glands which are iden- 
tical with v. GRAFF’s branchial sacs. They are situated in the 
posterior extremity of the body behind a vertical septum and below 
a cavity which Hansen designates by the name of pericardium and 
in which the widened portion of the dorsal blood-vessel, that may 
be termed the heart is suspended. The two glands communicate 
with the pericardial cavity by a ciliated opening and at the 
other extremity they open to the exterior by a ciliated duct on 
both sides of the branchiae. The walls of these glands are formed by 
a thin membrane which sends many folds into the interior cavity 
of the gland and by an epithelium of cylindrical cells. Small 
erystalline contents lead Hansen to the conclusion that these organs 
might perhaps be regarded as kidneys, 
Another very important fact which Hansen notices and figures 
