334 DR THOMAS SCOTT ON THE 



following stations : 25, 31, 44, 79, 82, 83, and 98. The first two stations are north of 

 the equator, viz., 15° 15' N., 25° 09' W., and 1 1° 10' N., 25° 20' W. The other stations 

 are south of the equator, Station 98 being in 34° 02' S., 49° 07' W. The Scotia specimens 

 differ somewhat from the drawings given by Steenstrup & Lutken in the work referred 

 to, in having the abdominal portion rather stouter and shorter, but they agree so well 

 otherwise that I have little hesitation in ascribing them to their species. Charles Branch 

 Wilson, in his work on " American Copepoda parasitic on Fishes," * describes a Dysgamus, 

 of which he obtained a single specimen, and his drawings show it to be not unlike the 

 specimens collected by the Scotia ; this Dysgamus he ascribes to a new species, 

 Dysgamus ariommus, and speaks of the fifth legs as being entirely lacking, whereas in 

 the Scotia specimens the fifth pair, as already stated, are, though small, quite distinct. 



Only one, or at most two, specimens were obtained in any single gathering, and 

 males only were observed, and, like the Caligus ropax frequently found in tow-net 

 collections in British waters, they were captured apparently as free-swimming 

 organisms. 



The only other writer who records Dysgamus is Dr Bassett-Smith in his work "A 

 Systematic Description of Parasitic Copepoda found on Fishes," published in Proc. Zool. 

 Soc. London, 18th April 1889. 



CLADOCERA AND OSTRACODA. 



Cladocera were very scarce in the Scotia collections. The few specimens observed 

 belong to the genus Evadne, two species of which are represented in the collection, 

 viz. : — 



Genus Evadne, Loven, 1836. 



Evadne tergestina, Claus. (PI. XIII. fig. 14.) 



This species occurred in a tow-net gathering collected at Station 85, 23° 8' 8., 

 39° 40' W. Only one or two specimens were noticed. 



Evadne spinifera, P. E. Miiller. (PL XIII. fig. 15.) 



E. spinifera was also obtained in the gathering from Station 85, 23° 8' S., 

 39° 40' \V , and was equally scarce with the species previously mentioned. 



OSTRACODA. 



The Ostracoda observed in the Scotia collections belong chiefly to the two groups 

 Podocopa and Myodocopa, and include representatives of the families Cyprida3, 

 Cytheridse, Cypridinidaj, and Conchceciadee. 



* "Nortli American Parasitic Copepods belonging to the Family Caligidae : Part II. The Trebinaj and 

 Euryphorinae," Proc. U.S.A. National Museum, vol. xxxi. p. 713, pi. xx. figs. 62-70. 



(ROy. soc. EDIN. TRANS., VOL. XLVIII., 580.) 



