184 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
and underneath this is the cutis, which is very indistinctly broken up 
into radial fibres; the internal cavity is divided by lamellar cross- 
sections of the root-processes of the hooks into eight sectors, and is filled 
by the plasmatic meshwork of the parenchyma and the nuclei of the 
cells that form it ; in it there lie the four equal cross-sections of the 
water- vascular and the two cross sections of the nervous system. 
A full consideration of this part of the body shows that the head- 
stalk is an integral part of the head. 
The Echinobothria do not live boring deeply in the wall of the 
intestine, like other Cestoda, but rather in the looser, superficial, partly- 
shed epithelia of the intestine and in its mucus, where they continually 
perform the most lively movements. One is almost led to believe that 
we must correlate with this the fact that the general structure of the 
head does not approach the four-rayed type so closely as that of the head 
of Teenia. On the whole, Echinohothrium appears to be what has been 
called a synthetic type ; by its double lobes of attachment and its head- 
stalk it has distinct relations to the Tetrarhynchidae, but by its rostellum 
it leans to the Taeniidae, by the generative organs (plan and form of 
yolk-stocks, and germ-stocks, closed uterus, and complete development 
of the proglottis), and partly by the hooks on its head-stalk, it is allied 
to the Tetrabothriidae ; at the same time it must remain in a distinct 
family. 
Helminthological Notes.* — Sig. F. S. Monticelli separates the genus 
Tetraonchus Diesing from Gyrodactylua and Dactylogyrus, supplies a 
revised generic diagnosis, and describes three species. He also de- 
scribes t Tristomum uncinatum sp. n., and a remarkable Distomum,X 
already named by Lopez D. richiardii, from the body-cavity of Acantliias. 
Its testes are numerous, and disposed in two lateral groups ; the internal 
receptaculum seminis is exceedingly large ; the vagina or canal of Laurer 
is absent ; the yolk-glands which lie beside the testes are small in 
proportion to the size of the animal ; their ducts meet in the middle of 
the body in a large vitelline receptacle. 
Bucephalus haimeanus.§ — M. Huet has a few notes on this somewhat 
rare parasite, which he found in Cardium edule. Such specimens as are 
infested have an unhealthy appearance, as Lacaze-Duthiers has already 
remarked. The lacunar tissue contains an enormous number of white 
filaments, which are sporocysts. In the interior of 4hese there are 
Cercarise in various stages of development ; the author has been unable 
to find the oesophageal tube described by Lacaze-Duthiers. An attempt 
was made to follow the life-history of this parasite, but all that can yet 
be said is that it seems to cause the death of its host and then escapes 
into the surrounding water. 
New Sporocyst from Cardium edule-H — M. Huet also describes a 
new sporocyst from G. edule. It is short, spherical, or pyriform in 
shape, and swims freely by means of the cilia with which it is invested. 
Forms were found in various stages of development, and even Cercarise 
* Boll. Soc. Nat. Napoli, iii. (1889) pp. 113-6. 
t T. c., pp. 117-9 (1 pi.). X T. c., pp. 132-4. 
§ Bull. Soc. Linn, de Normandie, ii. (1889) pp. 145-9 (1 fig.). 
11 T. c., pp. 149-51 (6 figs.). 
