42 M. Van Beneden on a new genus of Cestoid Worm. 
American specimens of C. virginiacus are somewhat larger 
than the Indian and Maltese ones. Both varieties however have 
been recently found by Capt. Drummond in Bermuda. In a 
list of the Birds of peaittt9 by Mr. H. B. Tristram, which is on 
the point of being published by Sir W. Jardine in his ‘ Contri- 
butions to Ornithology,’ these two varieties are regarded as di- 
stinct species, as appears from the following passage: “ No. 46, 
Charadrius marmoratus [i. e. virginiacus], American golden 
plover. No. 47,Charadrius..... ?, an unnamed species smaller 
than the American and perfectly distinct. Not unfrequent here. 
It has been also found in Malta by Capt. Drummond, 42nd 
R.H.” 
VII.— Notice of a new Genus of Cestoid Worm. By M. P. J. Van 
Benrpen*. Communicated by J. T. Antipexr, A.B., M.B., 
(Lond.). 
Tue researches of M. Beneden in the lower forms of animal 
existence have rightly secured him the reputation of an original, 
diligent, and careful observer ; and every communication there- 
fore from him deserves the attention of the naturalist. This 
leads us to give an abstract of his notice of a new genus of Ces- 
toid Worms, and of a proposed amended arrangement of them. 
M. Beneden discovered the new entozoon at the commence- 
ment of the spiral intestinal lamina of the skate, in company 
with other worms of the genus Bothriocephalus. Before enter- 
ing on its description, he would premise that, as the Cestoidee go 
through several phases of existence, a species is not represented 
by the adult state only, but by its several successive generations 
by gemmation, and of which the last only is furnished with 
sexual organs; and that it is consequently necessary to describe 
separately those various phases and to give them special names. 
Thus the first stage of existence may be called the scolexoid, 
being that of the scolewe or young worm on its escape from the 
ovuin ; the second, the s¢robiloid, from the word strobilus of 
M. Sars, designating the analogous stage of the Meduse; the 
third and last, the proglottoid, from the term proglottis, applied 
by M. Dujardin to the separated joints of the Cestoidee. 
Owing to the striking peculiarities of the newly-discovered 
worm, M. Beneden has felt it necessary to constitute a new ge- 
nus, of which it is at present the only example. This new genus 
is designated Echinobothrium, and presents the following cha- 
racters :— 
First, or Scolevoid generation, unknown. 
* Extracted from vol. xvi. of the ‘ Bulletin de Académie Royale de 
Belgique.’ 
