8 
Hymenolepis longior n. sp. 
REFERENCES. 
Dujardin, F. (1845). Histoire naturelle des Helminlhes. Paris. 
Grassi, B. (1887) (a). Die Taenia nana und iiire medicinische Bedeutung. Centralbl. f. 
Bakt. i. 4. 97. 
Grassi, B. and Calandruccio, S. (1887) ( b ). Einige weitere Nachrichten iiber die Taenia 
nana. lb. n. 10. 282. 
Grassi, B. (1887) (c). Entwicklungscyclus der Taenia nana. lb. n. 11. 305. 
Grassi, B. and Rovelli, G. (1889). Embryologische Forsehungen an Cestoden. lb. v. 11, 
12. 370, 401. 
- (1892). Ricerche embriologiche sui Cestodi. Alii Ace. Gioenia Sci. Nat. Catania (4), 
iv. 15. 
Johnston, T. H. (1913). Notes on some Entozoa. Proc. Roy. Soc. Queensland, xxiv. 63. 
Joyeux, Ch. (1919). Hytnenolepis nana (v. Siebold, 1852) et Hym. nana var. fralerna Stiles, 
1906. Bull. Soc. Path. exot. Paris, xn. 5. 228. 
Linstow, O. von (1896). Ueber Taenia ( Hymenolepis) nana v. Siebold und rnurina Duj. 
Jena. Zeitschr. xxx. 571. 
Nicoll, W. and Minchin, E. A. (1911). Two species of Cysticercoids from the rat-flea 
(Ceratophyllus fasciatus). Proc. Zool. Soc. 9. 
Stiles, C. W. (1906). Illustrated Key to the Cestode Parasites of Man. Bull. 25, Hyg. Lab. 
U.S. Pub. Health and Mar.-Hosp. Serv. Washington. 
Addendum. 
Since the preparation of the paper on Hymenolepis from rats, the author 
has seen descriptions of H. diminutoides, H. inexspectata and H. arvicolina 
given by Cholodkovsky in Ann. Mus. Zool. Ac. Sci., Petrograd, xviii. (1913), 
ppL 227-229. Although the names are here marked “spec, nova," they appear 
to have been first published in a catalogue of parasitic worms of the Army 
Medical Academy of Petrograd, in the previous year. It is this publication 
which was referred to as inaccessible, the redescriptions of 1913 having 
escaped notice. 
H. diminutoides and H. arvicolina belong to the unarmed group of species. 
The description of H. inexspectata is very brief, and scarcely suffices to deter¬ 
mine whether this species is distinct from that described by the writer as 
H. longior. The number and size of the hooks, the size of the suckers and the 
arrangement of the testes, as described, indicate differences which may be 
of specific importance, but the other differences are such as to be accounted 
for by a greater degree of muscular contraction, and it is impossible to lay 
any stress upon them. 
H. diminutoides is recorded from Microtus arvalis (Arvicola campcstris) 
as well as from the brown rat. H. straminea (Goeze, 1782), from Cricetus 
cricetus, should be added to the list of forms with armed scolex. 
