25 



It seems to me therefore undoubtful that the heterochseta found 

 by me differs in species from the hitherto completely known and 

 described forms of this genus. There is also reason to suppose 

 that it is just this species on which BOECK has based his description. 



What to me has been particularly decisive in the question of 

 identity is BOECK'S characteristic of the 5th pair of feet in the 

 male. It is true that in my specimens the upper antenna are not 

 shorter than the body, but this difference may depend on a wrong 

 judgment by the describer. 



From the south coast of Norway MOBIUS has mentioned a 

 heterochceta that is identified with BRADY'S species h. spinifrons 

 (1883). GIESBRECHT, however, has proved that BRADY'S spinifrons 

 is not the Mediterranean form (h. spinifrons, Glaus), but rather 

 h. abyssalis, Giesb. MOBIUS, however, mentions that in his spe- 

 cimens the first pair of antennse were longer than the body, and 

 as I have shown that this is actually the case in h. norvegica, it 

 becomes likely that it is this species that MOBIUS mentions from 

 Norway (Lindesnes). 



BOECK states no definite finding place; as before mentioned, 

 I took h. norvegica when gathering plancton, Feb. 25th, 1897, in 

 the Ofotenfjord; depth 250 m. The place is situated not far 

 from the telegraph station of Ledingen, which is in 68 24' N. 

 16 1' E. Grw. There occurred beside it, for instance cnlanus 

 hyperboreus and metridia longa. 



The hydrographical relations at the place where heterochceta 

 occurred are as follows : 



Temp. Saltness 



m. 2.0 C. 33.54 %o 



120 - 2.8 - 33.73 



150 - 

 250 - 



6.0 - 



6.1 - 



34.65 

 34.96 



The plancton was most abundant in the warm layer of 6 C. 

 Most of c. hyperboreus and metridia longa was found there, and 

 from this layer was probably also derived the norvegica, which in 

 its occurrence rather presents itself as an arctic species, at any 

 rate it is the first time that any heterochteta has been proved to 

 occur as far north as the 68th degree of latitude. 



Anomaloecra pattersonii, Templeton. 



During the North Ocean Expedition this species was observed 

 in the Sognefjord and at 6 different stations in the south part of 

 the North Ocean. I have taken it in the Herlo-fjord near Bergen, 

 and at Solsvik just south of Bergen, where in August 1895 it 

 occurred in great quantity. 



The species of acartia. 



Besides a. lonyiremis, I have, in plancton samples from the 

 Pudde-fjord off Bergen, observed a. clausii and a. discaudata, 

 Giesb. Of a. clausii, Giesb., I have also taken a single specimen, 

 a female, at Host (in Lofoten). I took the said specimen May 1. 

 1897 in plancton, 150 m. As far as I could judge, it showed 



a perfect agreement with the diagnose of GIESBRECHT. On the 

 rounded last thorax joint were several small points at the edge, 

 and the two foremost abdominal segments had a row of points at 

 the dorsal hinder edge. Length 1.5 mm. 



Females of a. discaudata have such a characteristic appearance, 

 that they cannot easily be mistaken for others. Some specimens 

 were observed in the autumn 1896 in the Pudde-fjord at Bergen. 



Oithona similis, Glaus. 

 Syn. : 0. pygmea. Boeck. 



There is every reason to believe that BOECK'S species o. pygmea 

 is synonymous with o. similis, Glaus. It is very common in the 

 plancton off our coast, and BOECK says of the pygmea, that it is 

 very numerous in the Kristiania-fjord in summer. The species is 

 easily distinguished from the following one by the rostrum forming 

 a right angle to the longitudinal direction of the body, so it cannot 

 be seen from the dorsal side. 



Oithona spinifrons, Boeck. 

 ? Syn. : 0. plumifera, Baird. 



The other form of oithona is rarer than the former one. I 

 have, however, seen it occured quite commonly in plancton samples 

 taken just outside the Biological Station in November 1896. On 

 loser examination it will perhaps be shown that the synonymy 

 suggested above is correct. The antennse are of about the same 

 length as those of o. plitmifera. but the projecting rostrum varies 

 somewhat from the drawing of GIESBRECHT in his well-known 

 "Monographic". The length of the females I have found to be 

 about 1.1 mm. 



Microsetella atlantica, Brady & Rob. 



From my plancton tables will be seen, that this species occurs 

 in winter as well as in summer. During July and August 1896 it 

 was very frequent in the fjords near Bergen, whereas it occurred 

 rather sparely off the Biological Station in February 1897. Nor is 

 it in Lofoten very frequent in winter. 



Harpacticus chelifer, 0. F. Miiller. 



BOKCK has observed this species in the Kristiania-fjord and 

 off the west coast of Norway. I have seen several specimens in a 

 sample taken at the quay at the village of Sundero in Vesteraalen. 

 This copepod also occurred in the stomach contents of young 

 green-cods that I caught at R0st in Lofoten. Otherwise the 

 species goes still further north, having been for instance observed 

 by AUKIVILLIUS in Kveenangen. 



