110 
of incubatory plates åre visible, viz. 2nd, 4th and 5th pairs; close 
to the hind edge of the 5th pair a pair of little acuminated appen- 
dages are to be seen, and on the hind edge of the right plate (but 
not on the left) a little bud-like prominence may further be seen. 
Each of the crests on the Sth pair of plates seems to have 12 
teeth. The 5th pair of plates are very large and contiguous in 
the middle line; this I cannot understand otherwise than that the 
animal is mature, though it has no ova. — Ova or d were not 
found. 
Fig. 11.  Holophryxus (Richardt ?). 
Dorsal, ventral and lateral view. 
The colour is (in alcohol) pale-yellow. 
The appendages on the Sth pair of incubatory plates I ap- 
prehend as showing that this specimen is the fully grown female 
of H. Richardi, and this I base on the following. (For the sake 
of convenience I call Koehler's specimen stage 1, the two others 
(from the ,,Tjalfe" St. 363 and 346) stage 2 and 3). 
1. The cephalon projects in stage 3 still more than in stage 
2, stage 1 has in front of the cephalon a broad projecting part; 
formed partly by the first pair of coxal plates. In stage 2 the 
. cephalon only projects a little midte the projecting part. In se : 
