ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
189 
provided with a variable number of prolongations, and aro unequally 
distributed in the granular layer ; where they accumulate they form tho 
so-called nerve-ganglia. It would seem that we have here another 
example of the influence of media on living beings. 
Anatomy of Myzomimus scutatus.* * * § — Dr. C. W. Stiles gives a 
detailed account of this Nematode, which is quite common in cattle 
slaughtered at the Washington (D.C.) abattoir. Even more important 
than this contribution to the anatomy of Eound Worms is the author’s 
conclusion that the individual variation among parasitic Nematodes is 
very great ; a complete series of connecting links can be found between 
extremes which one would at first be inclined to regard as specifically 
distinct. Care must, moreover, be exercised in making new species upon 
mathematical measurement, or upon the presence or absence of one or 
more pairs of papillae. Dr. Stiles’ observations show that the diagnosis 
of the family Filariidae must be broadened, for the form now described, 
which is an undoubted member of that family, has six pairs of pre-anal 
papillae in the male. 
Species of Gordius.j— Prof. L. Camerano describes Gordius aeneus 
from Venezuela, G. Dorise sp. n., &c., from Burmah. 
Species of Echinorhynchus.t — Dr. M. C. Francaviglia maintains 
that Echinorhynchus globocaudatus Zeder is really identical with Ech. tuba 
Rudolphi. 
7. Platyhelmintlies. 
Freshwater Dendroccela.§ — M. G. D. Chichkoff has made a study of 
Planaria lactea , P. polychroa, and P. montana sp. n. He finds that the 
cilia are more abundant and more active on the ventral than the dorsal 
surface. The outer investment of the body consists of a single layer of 
cells, which are cylindrical in form, and each of which is composed of 
two parts ; the upper is protoplasmic and the lower fibrillar. A delicate 
cuticle, devoid of pores, has been observed only in P. montana. The 
rods have a double membrane which bounds a cavity which is divided 
into several small chambers by transverse septa. It is difficult to say 
exactly what are the functions of these rhabdites, but there is no doubt 
that they give a certain consistency to the epithelium. The basal mem- 
brane consists of a delicate layer of more or less condensed granular 
protoplasm, and is, in all probability, formed at the expense of the 
parenchyma. 
The number and disposition of the layers which form the tegu- 
mentary musculature varies in different types, and even on different 
surfaces of one species. The outermost layer consists of transverse, and 
not, as is ordinarily stated, of circular fibres. Dorsoventral and 
transverse fibres are found in the interior of the body. 
The pigment of the parenchyma may be caused to disappear partially 
or altogether by the continued, and more or less prolonged, action of 
light. The ducts of the mucous glands never reach the surface ; there 
* Festschrift . . . Rudolf Leuckart, 1892, pp. 126-34 (1 pi.). 
t Ann. Mus. Civ. Stor. Nat. Genova, xxx. (1890-92) pp. 123-7 (1 fig.), 128-31, 
(2 figs.). t Boll. Soc. Rom. Stud. Zool., i. (1892) pp. 224-32. 
§ Arch. Biol., xii. (1892) pp. 435-568 (6 pis ). 
