ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
729 
pleuro-pedal connective which have been considered as characteristic of 
Gastropods are found also in the Lamellibranchiata. 
In Spondylus Lazardii the author had no difficulty in finding a 
ganglion lying near the visceral centre ; this he regards as the pleural 
ganglion, while the nervous band which connects it with the pedal centre 
is the pleuropedal ganglion. When these last are not apparent in a 
Lamellibranch it is because they have fused with other parts of the 
nervous system. In Mactra the author has found nerves which repre- 
sent in a simplified condition the stomato-gastric nervous system of 
Gastropods. 
o. Cephalopoda. 
Peculiar Chromatophores in a Cephalopoda — Dr. L. Joubin gives 
an account of certain chromatophores in the rare Chiroteuthis Bonplandii ; 
it differs in several particulars from the ordinary chromatophore. In 
form, it is swollen in the centre, on either surface, but especially below ; 
and the result of this is to greatly increase the thickness of the 
pigmented mass at the level of the nervous ending. It has the form of 
a biconvex lens. Its radial fibres are much shorter and more numerous 
than in ordinary chromatophores, and they have not the same fibrillar 
aspect. The nerve-ending is widened out, has a large nucleus, and is 
fitted with nerve-fibrils which are quite different from those found in 
non-modified chromatophores. The brown pigment is much denser than 
ordinarily. These facts lead the author to suggest that we have here 
to do with a thermoscopic eye. 
Swedish Cephalopoda.! — Among a number of memoirs recently 
received we have a careful revision of Swedish Cephalopods by Herr E. 
Lonnberg; it is to be hoped that the paper has long since been dis- 
tributed to those who are specially interested in the group. 
y. Gastropoda. 
Phylogeny of Docoglossa.!— Mr. W. H. Dali has a note on Dr. 
Thiele’s objections to his suggestion that the Lepetidae might represent 
the stem from which the Docoglossa were derived. He urges that in 
the Lepetidae there are to be found the greatest number of archaic 
characters, which point to their being nearest to the “Protolimpet.” 
Thiele would appear to have estimated too highly the constancy of minor 
details of the radula in single species. The relations of the radula in 
Lepetella to that of Lepeta , &c., offer additional reasons for thinking 
that the Lepetidae are of limpets those most nearly allied to normal or 
more usual types of Gastropods. 
Vallonia.§ — Dr. Y. Sterki’s observations on this genus of minute 
Mollusca allied to Helix are almost monographic. There are notes on 
the anatomy, shell, physiology, habits and geographical range, as well 
as full descriptions of the species, to which are appended a key and a 
table of geographical distribution. 
* Bull. Soc. Zool. France, xviii. (1893) pp. 146-51 (1 fig.), 
f Bill. Svensk. Vet. Akad. Hdlgr., xvii. IV. No. 6 (1891) 42 pp. (1 pi.). 
x Proc. Acad. Nat. Sci. Philad., 1893, pp. 285-7. 
§ Tom. cit., pp. 234-79 (1 pi.). 
