III.— ADDITIONS TO THE FAUNA OF THE FIRTH OF FORTH. 

 Part IV. By Thomas Scott, F.L.S. (Plates VII.-XIIL). 



This, the fourth contribution towards a better knowledge of the 

 fauna of the Firth of Forth, especially the invertebrate fauna, includes 

 among other interesting forms several species of Copepoda now described 

 for the first time, as well as a few not previously recorded for the east of 

 Scotland ; also a few species of Ampkipoda, rare, or not previously 

 recorded for the East Coast. 



The species here recorded or described for the first time for the Firth 

 of Forth comprise 25 species of Copepoda, 9 species of Amphipoda, and 

 a rare species of Actiniadce. 



A description (with figures) is also given of a species of Copepod pre- 

 viously recorded in Part III. of the Eighth Annual Report, p, 320, in 

 order to indicate more satisfactorily its position in the classification. 



In the preparation of this paper I have again the pleasure of gratefully 

 acknowledging the kindness of Professor G. S. Brady, F.R.S., also of 

 the Rev. A. M. Norman, F.R.S., Rev. T. R. R. Stebbing, M. A,, and A. O. 

 Walker, F.L.S. I am also much indebted to Dr T. Wemyss Fulton, 

 whose active interest in and sympathy with my work is a source of much 

 encouragement. I also desire to say that not a little of my success in the 

 study of the organisms recorded in this paper is due to the hearty co- 

 operation of Captain R. E. Simpson, and to the intelligent interest 

 shown by the mate in the investigations carried out on board the • Gar- 

 land.' My son, Mr A. Scott, has prepared the drawings which accompany 

 this paper. He has also largely assisted me with the preparation of the 

 dissections (a troublesome work) from which the drawings were made. 

 Without the drawings it would have been difficult to realise the important 1 

 and striking characters of the species mentioned, even though these 

 characters have been, where necessary, fully described, 



OKUSTACEA. 

 I, COPEPODA. 

 GNATHOSTOMA, 



Family Calanice. 



Acartia bifilosus (Giesbrecht). (PI. VII. fig. 14), 



1881. Dlas bifilosus, Giesbrecht, 'Die Freilebenden Copepoden 

 der Kieler Foehrde,' p. 147, pi. iii. figs. 4, 22, 23, &c* 



Habitat. — In the vicinity of Culross, near the head of the Forth 

 estuary, a* number of specimens were obtained among material collected 

 with a small beam- trawl-like tow-net, designed by Professor M 'In tosh, f 

 and worked from a rowing or small sailing boat. Acartia bifilosus closely 

 resembles Acartia longiremis, and requires to be very carefully diagnosed to 

 distinguish it from that species. The inner spines of the fifth pair of 



* Vierter Bcricht der Commission zur wissenclmftlichen Untersuchung. der deutschen 

 Meere, in Kiel, 1887-1881. 



t We find this net a most effective apparatus for capturing micro-organisms and 

 young fish sliould any be present to capture. 



