of the Fishery Board for Scotland. 315 



Acartia Clausii, Giesbrecht. — All the specimens of Acartia observed 

 belonged to the one species, viz., A. Clausii. This is quite a distinct form, 

 especially as regards the structure and armature of the fifth feet, and in 

 this respect it differs very markedly from Acartia longiremis, Lilljeborg. 

 So far as known, the distribution of Acartia Clausii appears to be even 

 more extensive than, though probably not so general as, Centropages 

 typicus. The area of its known distribution includes the Mediterranean 

 (Giesbrecht, Claus, Gourret, I. C. Thompson), Libreville, Gaboon River, 

 West Africa (Mini), Canary Islands (I. C. Thompson, Wimereux (Canu), 

 Plymouth (Bourne), Loch Fyne, Scotland (Norman), Firth of Forth, 

 Scotland (Mihi). The present seems to be one of the most northerly 

 records hitherto reported for this species. 



Oithona (?) similis, Claus. — All the ' Research ' specimens of Oithona 

 appear to belong to the species described by Dr Giesbrecht as Oithona 

 similis, Claus. Dr Giesbrecht seems to consider that most of the British 

 records of Oithona spinifrons are referable to this species, and he is 

 satisfied that Oithona spinirostris, Giesbrecht, is also identical with it. 

 The authentic distribution of Oithona similis is limited to a compara- 

 tively few places ; as, for example, Nice, Trieste, and Gulf of Naples in 

 the Mediterranean (Claus, Car, Giesbrecht), Kieler Fohrde (Giesbrecht), 

 Bay of Wismar, Baltic (Braun), West Baltic (Hensen), the Indian and 

 Pacific Oceans (Giesbrecht). 



Ectinosoma atlantica (Brady and Robertson). — This minute species 

 has to all appearance a world-wide distribution. Besides the various 

 records of its occurrence around the British Islands, it has also been 

 reported from the North and South Atlantic and the Pacific Oceans 

 (the Gulf of Guinea, West Coast of Africa, near Ascension Island ; and 

 near the Galapagos Island). Ectinosoma atlantica is so minute that it 

 has doubtless often escaped observation : it is sometimes a moderately 

 common species in Loch Fyne. 



Podon intermedins, Lilljeborg. — All the specimens of Podon observed 

 belonged to this species, which is readily distinguished from P. poly- 

 phemoides by the number of hairs of the second antenna — one branch 

 having seven and the other six hairs. 



Parathemisto (?) gracilipes, Norman. — None of the specimens of 

 Parathemisto obtained appeared to be mature, but, as far as could be made 

 out, they all belonged to P. gracilipes, which is a smaller species than 

 P. oblivia. 



