432 
MR. ROBERT GURNEY ON THE CRUSTACEA 
Macropsis slabberi, Van Beneden. 
This is strictly an estuarine or “ Brackish- water ” Mysid, 
not usually found in the open sea, but here it does not extend 
far up the rivers except with very high floods. During such 
salt tides it reaches as far as Acle. I have only found it in 
the Yare at Seven-Mile House. 
Macromysis flexuosa, Muller. 
Only a single occurrence, at a point between Runham and 
Stokesby in 1905, during a high salt tide. 
Heterotanais gurneyi, Norman. 
Norman, Ann. Mag. Nat. Hist. (7) vol. 
xvii. 1906. 
The specimens which were recorded in my 
earlier paper as “ Heterotanais, sp ? ” were 
submitted to Canon Norman for examination 
and were found by him to represent a species 
new to science. The species is closely allied 
to H. orstedi (Ivroyer), but differs from it in 
the shape of the cheliped. As Canon Norman 
does not give a figure of the male, one is 
given here. During the past year the species 
was found to be not uncommon. At Acle 
Bridge, in fresh water, it was twice found in 
abundance, hundreds being washed out of a 
piece of Cordylophora. It has occurred in 
the Bure by Ant. Mouth, in perfectly fresh 
water, and may be considered as a brackish- 
water species in the real sense, being capable 
of living in both fresh and salt water. 
u , 0 Cyathura carinata (Kroyer). See Plate. 
gurneyi, Norman. This species has not, so far as I know, been 
recorded hitherto from the British Islands. Its distribution 
seems to be as follows : — Eastern North America (New 
Jersey, Connecticut and Massachusetts), Greenland, Denmark 
and the Baltic. It has been described and figured by Norman 
and Stebbing,* and by Kuhlgatz,| but I think it worth 
* Trans. Zool. Soc. xii. 1886, p. 124. 
t Wissensch. Meeresuntersuchungen, 1898, p. 60. 
