50 TRANSACTIONS, NATURAL HISTORY SOCIETY OF GLASGOW. 



clausi of Giesbrecht, but the spines of the female fifth feet 

 are more slender and straight, or nearly so. In these Gulf of 

 St. Lawrence specimens the spines of the female fifth feet, 

 though moderately stout and curved, as in Acartia clausi, are 

 proportionally rather more elongated than in typical specimens 

 (see fig. 9). 



Acartia Giesbrechti, Dahl. PI. II., figs. 5-8. — A few specimens 

 of this species — chiefly males — were obtained in the gathering 

 from Shediac Bay. It resembles rather closely the Acartia 

 tonsa of Dana, discovered by that naturalist in the South Pacific 

 Ocean; but my son, to whom I am indebted for the identifica- 

 tion of the species, points out that in the female A. tonsa each 

 foot of the fifth pair ends in a spine, but in the female of 

 A. Giesbrechti each foot of the fifth pair ends in a slender seta. 

 The specimens were found in company with those of the 

 Eurytemora herdmani, already mentioned, and as Dahl's speci- 

 mens were obtained at the mouth of the River Tocantius, on 

 the north-eastern coast of Brazil, the normal habitat of the 

 species is probably estuarine rather than in the open sea. 



Professor Wheeler has recorded Acartia tonsa as common at 

 Wood's Hole. The occurrence of Acartia Giesbrechti in the 

 Gulf of St. Lawrence adds considerably to the distribution of 

 the species. 



Tortanus discaudatus, (I. C. Thompson and A. Scott).* — A 

 considerable number of specimens of this somewhat curious 

 species were obtained, especially in a gathering labelled " Tow- 

 ing net, Gulf of St. Lawrence, 1873." Though present in 

 gatherings collected o£E Griffins Cove and in Shediac Bay, the 

 number observed was much fewer. 



The species was described from specimens collected by Pro- 

 fessor Herdman near the island of Anticosti, in the Gulf of 

 St. Lawrence, and it was also found plentifully in plankton 

 collected somewhat later by the same gentleman in Pugit 

 Sound, on the Pacific Coast. The name Corynura was found 

 by Dr. Giesbrecht to be already in use, and substituted Tortanus 

 in its place. 



* 1897. Corynura diseaudata, Thomson and Seott, Trans. Liverpool 

 Biol. Soc, Vol. XII., p. 80, PI. VI., figs. 1-11. ; PI. VII., figs. 1, 2. 



I 



