THE TYPE SPECIES OF THE CESTODE GENUS HYMEXOLEPIS. 
By Ch. Waedell Stiles, Ph. D., 
Chief of Diiision of Zoology, Hygienic Laboratory, U. S. Public Health and Marine- 
Hospital Service, ' 
The determination of type species for certain genera is not unattended 
with difficulties and with differences of opinion. Hymenolejns^ for 
example, presents an instance in regard to which helminthologists are 
not in accord. The premises of the case are these: 
(1) Weinland (1858, § 68, pp. 49 to 5T) proposed the genus Ilyinen- 
olepis. (2) He did not specifically state that any particular species was 
chosen as a type; (3) but he combined only one specific name, namely, 
flavop>un€tata {—Tsenia dimhiuta) ,, Ilymenolejns (see Weinland, 
1858, pp. X, 16, 49, 52, 53, 55, 57, 58, 75, 85, 92). (4) His discussion 
of the genus is based on this form. (5) In a footnote, pp. 50 to 53, to 
this discussion, he reviews the classification of certain tapeworms and, 
p. 52, he mentions Hyinenolepis. (6) This genus he there dixfides into 
two subgenera, namely, (7) Subgenus 1. Lepidotrim^ stating "•As 
the type, we may consider Tsenia murina Dujardin; and besides this 
belong here Tdenia scalcrns^ , and Hymenolejyisdavojyunctata.^' (8) 
Subgenus 2. Dilepis , “and we may consider Tdenia angidata 
Rudolphi as its type.” (9) In Dilepis he also placed, besides other 
species, “the Teenioid of the golden-winged woodpecker, mentioned 
abox^e, § 28.” (10) The latter form is evidently Liya punctata, de- 
scribed in 1857 as new species from Picus auratus (=the dicker, Colaptes 
aumtus (Linnaeus, 1758), Vigors, 1827), as is seen from the description 
of the testicles. (11) Liya punctata is type and only species of Liya 
Weinland, 1857. 
In this case, therefore, at the date of 1858 we hax’e four generic 
names 1858; Lepidotrias^ 1858: Dilep>is,lSb^\ 2 a\d,LJya, 
1857) to deal with, and of these Weinland should undoubtedly hax^e 
used Liya instead of proposing ILyinenolep>is. 
Types were definitely fixed for Lepidotrias. namely, Tdenia murina 
Dujardin, 1845 (not Gmelin, 1789)= /a nana x’on Siebold, 1852, 
which is also type of Diplacanthus Weinland, 1858 (not Agassiz, 1842); 
for Dilepis^ namely, T. anyidata; and for Liya^ namely, Z. punctata. 
As the subgenus Dilepis. 1858, contained the older genus Liya. 1857, 
Weinland should not hax^e proposed but since he definitely 
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