ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
175 
Nematoid worms were rarely found. Only twelve specimens of Mollusca 
are recorded, and parts of Vertebrates — such as feathers or hair — are very 
rare. The nearest allies of the amber fauna are, to-day, found in North 
America and Eastern Asia. 
B. INVERTEBRATA. 
Notices of Entozoa.* — Prof. J. Leidy draws attention to the discovery 
in Simia satyrus (the Orang) of Ascaris hmibricoides and TrichocepTialus 
dispar, which are common parasites of Man. With them were found 
examples which are provisionally placed in the genus Filaria and called 
F. (?) primana sp. n. Ascaris diacis from the body-cavity of Quiscalus 
quiscala and A tract is (. Ascaris ) opeatura from the Iguanid Cyclura 
baelopha are new. About a pint measure of Trichocephalus affinis was 
taken from the large intestine of the Bactrian Camel. Several dozen of 
Cheilospirura uncini'penis were found in the gizzard of BJiea americana. 
Trichosomum ? tenuissimum sp. n. was found imbedded in the liver of a 
mature Brown Bat. A dozen females of Fchinorliynchus pellucidus were 
found attached to the lining membrane of the intestine of a whale, Meso - 
plodon sowerbiensis ; F. paucihamatus sp. n. was frequent and abundant 
in the small intestine of the Black Bass ( Micropterus nigricans ). Five 
new species of Distomum are recorded, as are two new Cestodes. 
Fentastomum proboscideum is reported from Coluber constrictor and the 
Skunk ( Mephitis mephitica ). 
Mollusca. 
a. Cephalopoda. 
Development of Chromatophores of Octopod Cephalopoda.f — M. L. 
Joubin has been able to study the development of the chromatophores 
in the Argonaut and the Octopus. In the embryo of the former the 
skin is composed of an ectodermal epithelium, which covers a loose 
mesodermal connective tissue. In the dorsal interocular region one may 
best see scattered ectodermal cells becoming longer than those around 
them ; they then gradually sink into a kind of funnel-shaped depres- 
sion, taking with them the neighbouring cells. The large cell is 
destined to form the essential part of the chromatophore ; as it becomes 
very large its protoplasmic contents are divided into two layers. This 
cell is, later, only attached by a narrow surface to the invaginated 
ectodermal cells, and finally becomes free; later on it loses its spherical 
form and becomes a biconvex lens. 
Meantime, changes have been going on in the mesodermal cells ; 
below the invagination they are disposed by five or six, in a circle, but 
they soon increase to twenty and form a larger circle ; in form they are 
ovoid and elongated. The edge of the ectodermal cell then comes into 
contact with this crown of ovoid cells and the chromatophore is formed. 
The accessory mesodermal parts at first resemble muscular fibres, but 
later on become connective. The nerve-endings in each chromatophore 
can be shown in a living animal by a special preparation of methylene- 
blue. The cutaneous nervous plexus with each fibre ending in a slight 
swelling can then also be seen. 
* Proc. Acad. Nat. Sci. Philadelphia, 1890, pp. 410-8. 
f Comptes Rendus, cxii. (1891) pp. 58-60. 
