1887] Zoology. 187 
agony we quote (from the résumé) in full: “I cannot agree 
Beard in regarding the Myzostomida as belonging to the 
Paecspods. there are too many dissimilar features in their struc- 
ture, and I do not think that their development, as described by 
ard, is ‘quite that of a Chztopod.’ The absence of a preoral 
ring of cilia, the relatively small development of the preoral lobe, 
and the great development of the body part of the larva are no 
insignificant differences; they show that the larva is not a little 
differentiated. The presence of a preanal ring of cilia is com- 
n to most Annelid larve, and the larve of Mollusca, Bryozoa, 
etc., also usually possess such a ring. In the absence of this ring, 
as well as in the rudimentary development of the preoral lobe, 
the larve of Myzostomida resemble those of Sipunculus; in 
their general structure there is, however, but little resemblance 
to be traced. I am inclined to regard the Myzostomida as a 
peculiar, distinct group, belonging to the Daid, related to the 
Chætopods, but also showing a tendency towards some of the 
Arachnids (Linguatulida, Tardigrada, and perhaps Pycnogonida) 
and Crustaceans; they are sprung from the Trochophora; amon 
the Archianelleda their ancestor has been chiefly related to that 
of Histiodrilus; on the other hand, it has also been related to 
that of the Arthropods, because the Myzostomida really show, 
in their structure, a tendency towards these. They are therefore 
one of those groups presenting the greatest interest as a subject 
for phylogenetic studies.” The present reviewer fails to recog- 
nize the EE ge resemblances of these forms. He is in- 
clined to regard them as Annelids but remotely related to the 
Chetopods, parasitism having extensively modified them. 
Anatomy of Echinorhynchi.—The Acanthocephali have been 
regarded as devoid of a digestive apparatus, and Lespés'’s discov- 
ery of what he considered the alimentary tract in the pyriform 
body in the proboscis of Echinorynchus claviceps, met with but 
little acceptance. Recently AE n has been studying the sub- 
ject, and gave the result of his researches before the Scientific 
Congress of Paris. In order to settle the question it was neces- ` 
sary to study these worms at a period before the development of 
the sexual organs, and when the nutritive system was in full 
function. Megnin found Echinorhynchi encysted in the cellular 
tissue of some Varanidæ from the Sahara. These proved to be 
in a larval stage and to have a digestive apparatus composed of 
two long convoluted tubes, each giving rise to numerous cecal 
diverticula. The whole — an analogy to the alimentary 
tract of the Trematodes. In some species, as the Æ. brevicollis 
found in Lalenoptera sibbaldi, ee aeea apparatus persists 
and acquires considerable development. In others it undergoes 
a degeneration and is to be sought in the “lemnisci,” structures 
heretofore of problematical nature, occasionally regarded as sali- 
