ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
635 
New Heterakis.* — Dr. Magalhaes describes a new species of Hete- 
rdkis from the domestic fowl, which he calls H. brasiliensis, and he 
points out the differences between it and the four species of the same 
genus which are already known to live in Gallus gallinaceus . 
y. Platyhelminthes. 
Nemertines of Plymouth Sound.* — Mr. T. H. Riches enumerates 
thirty-three species of these worms from Pymouth Sound. Of these, 
four are new, viz. Tetrastemma nigrum , T. immutabile , T. ambiguum, and 
Amphiporus dissimulans ; Nemertes Candida is new to Great Britain; 
Carinella polymorpha and Micrura aurantiaca have not been previously 
recorded north of the island of Herm, and DrepanopJiorus rubrostriatus 
has not till now been recorded north of Guernsey. 
Although the Nemertines exhibit brilliant colours, and although 
many are conspicuously marked, the author has not been able to find 
any very definite relation to the surroundings. Varieties have been 
obtained which in many respects connect such well-marked species as 
Tetrastemma candidum, T. vermiculatum , and T. melanocephalum. The 
author adopts Burger’s classification into the orders Protonemertini, 
Mesonemertini, Metanemertini, and Heteronemertini. 
With regard to the spawning periods it may be stated generally that, 
during the whole year some one or more species are breeding, and a 
large number of species were found with ripe generative products from 
late summer to the middle of December, when the author left Plymouth. 
CephalotJirix bioculata has been successfully bred in captivity, and it 
is hoped that an account of its development will shortly be published. 
A very interesting description is given of the variations of Tetrastemma 
candidum , of which we may particularly note one that only differed 
from the reddish variety of the species with regard to the anterior pair 
of eyes ; these, instead of being compact and round, were broken up 
into two little masses of minute specks, invisible except under the Micro- 
scope. A case in which a relation could be detected between the colour 
of the animal and that of its surroundings was afforded by T. melano- 
cephalum, a specimen of which, found among red weeds, was coloured by 
minute red-brown pigment-granules. 
Turbellaria of Plymouth Sound.}; — Mr. F. W. Gamble, who has lately 
published a memoir on British Marine Turbellaria, § now gives a list of 
the species found in the neighbourhood of Plymouth. He had here to 
do with a practically unworked field. About 18 per cent, of the species 
found are known to occur in the Mediterranean. Of the fifty-six species 
but few are new, and several are known to occur in Scandinavian waters. 
Specimens were obtained by collecting sea- weeds and placing them in 
vessels of sea-water ; thence the Rhabdocoeles emerged in great numbers, 
especially towards night, and could be picked out with a pipette ; another 
way is to use a hand-net, in the mouth of which a sieve is placed to 
prevent the entrance of bulky weeds; the dredge also brought up a 
large number of interesting forms, and examination of the dredge- 
* Bull. Soc. Zool. France, xvii. (1892) pp. 219-21 (1 fig.). 
t Journ. Mar. Biol. Ass., iii. (1893) pp. 1-29. J Tom. cit., pp. 30-47. 
§ See this Journal, ante , p. 479. 
