[3] ENTOZOA OF MARINE FISHES OF NEW ENGLAND. 455 
In the descriptive part of this paper I have confined my attention to 
the Cestoidea and the Acanthocephala, and with two exceptions, viz, 
Dibothrium alutere and Echinorhynchus sagittifer, to adult forms. 
In the determination of genera I have been guided principally by 
Diesing’s Revisions. Accepting the characters there enumerated, I 
have been compelled to create three new generic names, viz: Spongio- 
bothrium, Crossobothrium, and Phorevobothrium. 
For the determination of species [ have made use of the palicstions of 
Rudolphi, Diesing, P. J. Van Beneden, Dujardin, Von Linstow, Wagener, 
Krabbe, Olsson, Eschricht, Leuckart, Kiichenmeister, Ziirn, Von Sie- 
bold, Leidy, Cobbold, and others. 
Systematic work on the Entozoa is attended with much difficulty on 
account of the confusion in which the earlier literature is involved. In 
this connection I take the liberty of quoting a brief passage from Von 
Linstow’s ‘‘ Compendium der Helminthologie,” Hannover, 1878: 
‘The number of well-founded species is indeed not quite so great as 
the list indicates, for a host of older names, especially originating with 
Rudolphi, figure in it, of which typical examples are no longer in ex- 
istence, and which have been described imperfectly or not at all, so that 
they must remain forever an unsolved riddle. For example, many rudi- 
ments of Teniw discovered by this author, whose enumeration has been 
of not the least advantage to science, and many descriptions of older 
date have not since been recognized. One comes from their contem- 
plation often in great perplexity of mind, and does not really know how 
they ought to be represented. Moreover, to make the entire literature 
effective was impossible, since too many species are described in such 
a way that it is not possible to recognize them again, and other specifi- 
cations are so improbable that for this reason they must remain uncon- 
sidered; * * * when further the description of a new species is dis- 
posed of with an enumeration of the length and breadth, when, finally, 
for new species only the place where they are found is given, together 
with or without an accompanying description, as is to be found in many 
works, then I think I am not at fault in citing such publications only 
in Jimited amount.” 
It has been my endeavor to give as full a description of each species 
considered as the material at hand would justify. When only alcoholic 
Specimens were accessible I have mentioned the fact in the proper 
place. 
As the development of many of the Cestoidea seems to be quite differ- 
ent, even in closely related forms, it is very important that the sys- 
tematic work which is done on them be so done as to leave no doubt in 
the mind of the investigator what species is being described, whether 
the name adopted for it holds or not. Appreciating the value of figures 
in establishing the identity of species, Ihave therefore not included 
in this paper descriptions of any forms unless accompanied with sufii- 
cient figures to make future identification reasonably certain. 
