368 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
INVERTEBRATA. 
Microfauna of Samoa.* — Dr. A. Kramer gives a picturesque de- 
scription of a wood-lake in Samoa, enclosed by a crater-wall and encircled 
by palms. It abounds in vegetable debris, but contained few animals. 
He collected two new species of Cyclops , and another Copepod ; Dapli- 
nella, Macrothrix , Alona , and other Cladocera ; a small Nematode, and 
some insect larvae. The point of his note is rather to emphasise the im- 
portance of studying the freshwater Plankton in these regions, for it 
seems to be one of the last things that even the naturalist traveller thinks 
of doing. 
Mollusca. 
Skill-Glands of Molluscs.f — Dr. J. Thiele discusses the minute 
structure and homologies of the skin-glands in a large number of 
Molluscs. Thus he compares Haliotis and Area as follows : — 
Haliotis. Area. 
Anterior foot-gland. 
Lip-gland. 
Sole-gland. 
Peripheral goblet-cells. 
Sole. 
Anterior foot-gland. 
Mucus gland in foot-groove. 
Byssus-gland. 
Posterior mucus-gland. 
Peripheral mucus-glands. 
Foot-groove and Byssus-cavity. 
All the skin-glands have this character in common, that they are 
composed of glandular cells and supporting cells. The latter constitute 
a meshwork in which the former are wholly or partly imbedded. The 
author proposes to use this character as a means of distinguishing the 
skin-glands from those of the mesoderm and endoderm, and gives a 
number of examples corroborating the distinction. 
Molluscan Fauna of Freshwater Lakes in Central Celebes.}: — 
Plerren P. and F. Sarasin direct attention to the remarkable molluscs 
which live in the large and deep inland lakes of Celebes. The forms 
they were able to capture point to the existence of a fauna perhaps as 
interesting as that of the Lake of Baikal. The authors begin with a 
new Gasteropod — Miratesta celebensis, for the reception of which it seems 
necessary to establish not only a new genus, but a new family (Mirates- 
tidse). The structure, which is briefly described, shows a combination of 
characters distinctive of various families. The animal is nearest the 
freshwater Pulmonates, especially the Limnseidse, as is suggested by the 
Planorbis- like structure of the radula, the nervous system without 
chiastoneury, the hermaphroditism, and the absence of an operculum. 
But any very close affinity is impossible, as is shown by the large gills, 
the very peculiar pouched feelers, and the structure of the shell. Dis- 
tant relations may perhaps be found in the so-called Thalassophilac 
( Amphibola and Siplionaria'). In any case, the family is phylogenet- 
ic ally old, near the base of the freshwater Pulmonates. 
* Zool. Anzeig., xx. 1897, pp. 135-6. 
t Zeitschr. f. wiss. Zoo]., lxii. (1897) pp. 632-70 (2 ids.). 
X Zool. Anzeig., xx. (1897) pp. 241-5 (2 figs.). 
