88 
Observations on Polyzoa, sub-order Phylactolaemata. 
With 9 plates. By Alpheus Hyatt. Proceedings of the 
Essex Institute, vols. iv and v, 1866 — 1868. Salem, 
Mass., U.S.A. — A very careful and valuable description of 
the organization of the fresh-water Polyzoa. Many histo- 
logical details are given, and some remarks on general 
homologies are offered. We cannot agree to any “neces- 
sity ” for speaking of the fixed end of a polyzoon as its 
“ anterior,” and the free end as its “ posterior ” extremity. 
Anterior and posterior in relation to what? If in relation 
to the activity of the animal, then assuredly the oral ex- 
tremity must be called — as is usual — “ anterior.” But 
“ anterior” and “ posterior” are bad words to use in homo- 
logical nomenclature. They then mean nothing. Three spe- 
cimens of Fredericella, four of Plumatella, one Pectinatella, 
and one Cristatella, are here described. The plates are 
executed in white on a black ground. Synoptical tables of 
great precision and detail are given. 
Observations on British Zoophytes and Protozoa. By 
T. Strethill Wright, F.R.S. 1 plate. Proc. Roy. Phys. 
Soc. Edinb., vol. iii. 
On the Anatomy of Gordius. By Dr. H. Grenadier. 
Zeitschrift fur Wissenschaftliche Zoologie, September, 1868. 
— In this contribution is given a full description of the 
anatomical composition of Gordius' ornatus taken from the 
abdomen of a Mantis in the Philippine Islands. The result 
of Dr. Grenacher’s investigations on this specimen, which 
was a female, and also on specimens of G. aquaticus and 
G. subbifurcus, differ from those previously reported by 
Meisner, particularly with regard to the termination of 
the intestinal canal and the generative organs. The so- 
called excretory orifice at the posterior extremity of G. 
ornatus leads into a cloaca, the lining membrane of which 
is evidently an inward extension of the external integument, 
as it is covered hy • short pointed papillae. This cloacal 
cavity is surrounded by circular fibres of a muscular cha- 
racter; superiorly, it is continuous with a wide tube which 
forms the receptaculum seminis. In the front wall of this 
tube, near the opening of the cloaca, is the slit-like orifice 
of the intestinal canal. A section through the body of the 
creature, near its extremity, presents four tubes : two lateral, 
the oviducts, and two median, the receptaculum seminis 
and the intestine. The oviducts are somewhat tortuous, and 
terminate in front in the ovaries, which in this specimen 
were distended with closely packed polygonal cells. The 
intestinal canal passes, for a short distance, in front of the 
