ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
599 
The larval excretory organs appear at a very early stage, and con- 
sist of large vacuolated cells. These are probably! secondary organs, 
adapted for life in a cocoon. The author’s observations on the pro- 
nephridia of the embryo do not wholly agree with those of any previous 
observer. He finds that they originate in the head-cavity into which 
they open, are lined with cilia, and exhibit very distinct nuclei. They 
appear to transmit the products of metabolism from the head-cavity to 
the exterior. The author doubts the j>ossibility of homologising the 
pronephridia of leeches and Oligochsetes, at least in any detail. 
Kinberg s Qligochsetes.* — Hr. W. Michaelsen has re-examined the 
collection of Oligochaites originally described by Kinberg. f The col- 
lection consisted of specimens taken by the ‘ Eugenie 5 expedition and 
some other specimens in the Stockholm Museum. Kinberg’s descrip- 
tions and diagnoses were mostly very inadequate, and Michaelsen refers 
his genera and species to their true position, rejecting many of the 
species as based on immature specimens. 
Supposed Encystment of Pachydrilus catanensis Drago.J — Hr. 
Luigi Cognetti has a short note on this species. Hrago § described it as 
undergoing encystment, the cysts containing two small individuals, dis- 
playing all the characters of the adult worm, but of small size. These 
and the other characters of the “ cyst ” are so remarkable and so dif- 
ferent from the conditions seen in the encystation of JEolosoma , that 
Cognetti is unable to accept the term. He believes that the “ cyst ” is 
nothing but the cocoon displaying all the characters common to the 
cocoons of other Enchytraeidae. 
Snow-inhabiting Enchytraeid.|| — Mr. J. Percy Moore describes 
Mesenchytrveus solifugus Emery collected upon the snow of the Mala- 
spina Glacier on Mount St. Elias. A very striking peculiarity of the 
species is the yellow-brown, deep chocolate-brown, or almost black 
colour, and its opacity. This melanism — whatever be its explanation 
— is known in many other snow-inhabiting animals. The author briefly 
discusses the problem of coloration, and also the more general one sug- 
gested by the fact that this snow-worm lives and grows while maintain- 
ing a bodily temperature about the freezing point of water. 
Structure of Thalassema neptuni.1T — Mr. H. Lyster Jameson has 
investigated the anatomy and histology of this Echiuroid. He finds 
that the body-wall consists of an external cuticle and an epidermis 
which contains four different types of elements. Beneath the epidermis 
lies the cutis, three layers of muscles, and a peritoneum. The digestive 
organs consist of fore-gut, made up of pharynx, oesophagus, gizzard 
and crop, mid-gut or intestine, and rectum. The intestine exhibits a 
reversal of the ordinary relations of the musculature (cf. Capitellidte). 
It is divided into three parts, of which the median has a collateral 
intestine continuous at either end with a ciliated groove lying in the 
anterior and posterior regions of the intestine. Remarkable glands 
occur in crop and oesophagus, and possibly secrete the mucus found 
* Ofvers. K. Vet-Akad. Fdrh., Ivi. (1899) pp. 413-48. t Op. cit., 1866. 
X Zool. Anzeig., xxii. (1899) pp. 381-3. § Ricerche R. Univ. Roma, vii. (1899). 
IJ Proc. Acad. Nat. Sci. Philadelphia, 1899, pp 125-44 (1 pi.). 
U Zool. Jahrb. (Abt. Anat.), xii. (1899) pp. 535-566 (3 pis. and 1 fig.). 
