22 Nils Hj. Odhner. 
coecum, as well as in the interior of the intestine, there appear 
numerous openings in the wall leading into the branching inter- 
septal diverticula. 
In the bipartition of the dorsal coecum, as weil as in the 
thin ventral pharyngeal sac, behind which the salivary glands 
open, the present species differs from D. vampyrella, which has | 
a simple coecum, a pharynx with uniformly thick walls and with — 
terminal openings of the salivary glands. 
Alexandromenia crassa n. sp. 
(Figs. 25—34). 
Body rather short and broad, depressed towards both ends 
which are rounded, the anterior one broader. Dorsal side with 
a narrow median keel. Ventral side flattened, with a relatively 
broad median furrow continuous with the cloaca, and containing 
11 folds of equal height, except the median one which is only 
slightly prominent. Cloaca ventral with about 10 gill folds pro- 
jecting perpendiculary from the margin and with two longitudi- 
nal ones in the roof at the sides of the anus. Mouth ventral. 
Pharynx circular with a few dorsal glands and a pair of small 
salivary glands opening into the radula sac. Radula monoserial 
with broad plates (0,16 mm in breadth) from which rises a tooth 
with a projecting denticle on each side and the concave inter- 
space furnished with 7—8 smaller denticles. 
Cuticula thick with large masses of needle-shaped hollow 
spicula with rather thick walls (fig. 29), of varying sizes and 
crossing each other in all directions. Hypodermis papillae mul- 
ticellular: their stalks narrow and their heads dilated with trun- 
cated upper sides due to their being composed of many cells 
situated side by side in an equal height (fig. 30). 
Dorsal coecum of the intestine extending beyond the brain. 
Coelomoducts small and simple, furnished each with a single 
receptaculum seminis in front of the pericardium; shell gland 
with a short unpaired distal part (,precloacal organ“) opening 
beneath the anus. No copulatory organs. 
Colour white. Length of animal 10, height 3, breadth 3,3 mm. 
Locality: Faerøskalle, Hjeltefjord, 100—200 m. (°/s 1913; B). 
There are so far known two species of the present genus, 
