576 GILBERT C. BOURNE. 
6. Monstrilla anglica, Lubbock (‘ Ann. Mag. N. H.,’ 2nd 
ser., xx, p. 409). Monstrilla Dane, ¢ Claparéde, ‘Beobacht. 
iib. Anat. u. Entwick.,” p. 95. Cymbasoma Herdmani, 
I. C. Thompson (‘ Proc. Liv. Biol. Soc.,’ 11, p. 70). 
Four abdominal segments. Antenne of the male five- 
jointed, the two last joints subequal, hinged on each other to 
form a grasping organ. Hab. Weymouth, Cherbourg, Channel 
Islands, Liverpool Bay. 
Dana placed the Monstrillacea under his sub-order Cor- 
mostomata, of which it forms the first tribe, the sub-order 
including the Caligacea, Lerneacea, andthe Nymphacea, 
Claparéde very justly remarks that Monstrilla has no resem- 
blance to any other members of the Cormostomata, and pro- 
ceeds to point out a resemblance between this genus and the 
Pontellidz, apparently because of the similarity of the eyes ; 
Monstrilla, however, differs entirely from the Pontellide 
in the character of its antenne. Claus (op. cit., p. 48) points 
out the resemblance of the eyes of the Corycxide to those of 
the Pontellida, without attributing any relationship on this 
account. In the same way the eyes of Monstrilla are similar 
to those of the Corycewide, and this, taken together with the 
character of the antennz, the reduction of the mouth parts, and 
the habit of the animals, seems to justify the position of Mon- 
strilla among the Coryceide, where it was placed by Claus. 
There are no grounds for Thompson’s family of Cymbasoma- 
tide, nor for placing Monstrilla among the Artotrogida, 
as he has done in his first notice of the genus. 
The aberrant character of the genus, however, might warrant 
us in regarding the Monstrillide as a separate sub-family of 
the Coryceide. | 
It will be noticed that nearly all previous authors have 
regarded Monstrilla as a parasitic form, for no other reason 
than the absence of mouth parts and alimentary tract. Ex- 
cepting this character, there is no evidence for attributing para- 
sitic habits to the genus. Every specimen that has yet been 
caught has been found in a free pelagic condition. The living 
animal is extremely lively, and swims with an energy unusual 
