BY T. HARVEY JOHNSTON AND B. BUCKLAND TAYLOR. oil 
measuring .03mm. in length; the eyes are large but not 
pigmented. There are 9 jaws on each side, in form like 
those of Eukrohnia subtilis, the point not being inserted 
into the shaft, but they are more curved. The corona 
is almost circular, and lies on the neck and body. The 
animal is widest at the septum, where it measures (exclud- 
ing fin) 0.4 mm. #.e., 11.7% of the total length, and then 
tapers gradually towards the neck and tail. The lateral 
fin commences on front of the receptaculum seminis. It 
reaches its maximum width (which is 18% of the total 
length of the animal including the tail fin) in front of the 
tail, then narrowing in the region of the seminal vesicles, 
where it becomes confluent with the tail fin. The latter, 
as well as the lateral fins are entirely traversed by rays. 
The ovaries extend into the vicinity of the ganglion the 
ova being few and relatively very large (0.2mm.) A small 
receptaculum seminis opens on the dorso-lateral surface 
on each side just in front of the tail septum. The aperture 
is situated on a well-marked rounded prominence with a 
swollen extremity and a rather narrower stalk-like portion. 
The actual opening is trilobed in our specimen. The tail 
measures 56.5% of the total length. Most of its coelome 
is filled with sperm morule, the testis occupying only 
a small anterior position. The vesicule seminales are very 
small and inconspicuous, and lie in the posterior third of 
the tail, at the narrowest part of the fin width. The tail 
fin arises from the dorsal surface and there 1s a differenti- 
ated zone at the posterior end of the tail. There are sensory 
patches on both the lateral and tail fins. Two club-shaped 
papillated bodies are present on the posterior half of the 
tail, lying on the ventral surface at the right side. Though 
they became stained like the tissues of the animal, as a result 
of the use of hematoxylin, yet their asymmetrical arrange- 
ment and general appearance suggest that they are foreign 
bodies—perhaps of an algal nature. The largest measures 
-0.14mm. in length and 0..06mm. in maximum breadth ; 
the other 0.10 and 0.04mm. respectively. 
The following measurements were taken from the 
animal while in formalin ; Length, including tail fin, 3.68 
mm.; tail, 56.5% of total length; maximum breadth, 
