i88 7 .] 
The Norw. North-Atlantic Exped. 
23 
Fig. 8. A portion of the connective-tissue membrane which con- 
nects the reproductive organs to the septum; magnified. 
a. Connective-tissue membrane. b. Ovaries. c. Testicles. 
» 9. Connective-tissue membrane with the testicles: magnified. 
a. Connective-tissue. b. Cells on the inner wall of ' the 
testicular tubes (spermatobiasts). c. Similar cells filled 
with undeveloped spermatozoa. d. Loosened undeveloped 
spermatozoa. e. More perfectly developed spermatozoa. 
» 10. Connective-tissue membrane with ovaries: magnified. a. 
Connective-tissue. b. Ova. . 
» 11. Transverse section of integument and intestine of the 
posterior part: magnified. a. The mesial part of a septum. 
b. Fillet-formed connective-tissue prolongations on the outer 
wall of the rectum. Attached ova are seen on the septa. 
» 12. Oral disc with tentacles; superior aspect, magnified. 
» 13. Transverse section of the bottom of a chamber, with a 
portion of the rectum. a. The fissure at the bottom of 
the chamber. b. Rectum. 
» 14. A portion of the outer surface of the integument, on 
which suckers are seen, magnified. 
Plate II. 
» 1. Ægir frigidus, natural size. 
» 2. Transverse section of the body integument of Fenja mi- 
rabilis, magnified. a. Cylinder-epithelium (Ectoderm). b. 
Unicellular mucous glands, c. Nematocysts. 
» 3. Transverse section of the superior portion of the gullet- 
tube, close to the oral disc of Fenja mirabilis; macerated 
preparation, magnified. a. Nerve-reticulation. b. Epithe- 
lium. c. Muscles. d. Ganglial cells. The epithelium is 
torn a considerable distance away from the muscular layer. 
» 4. Nervous ganglia, and swollen nervous threads from the 
inferior portion of the oral disc and the adjoining portion 
of the body integument of Fenja mirabilis, magnified. 
a. Nervous ganglia, b. Swollen nervous threads. 
» 5. Ægir frigidus: magnified. a. Protuberant ribs. b. Longi- 
tudinal areas between the suckers. c. The exposed part 
of the body. d. An excrementory plug passing through 
the anus. 
