20 



Bipinnaria. 

 In Feb. 1896 I took hynnnaria at several places along the 

 west coast. The small five-armed sea-stars could distinctly be seen 

 on all, and the arrangement of the processes on the larvae makes 

 it likely that all must be classed among bipinnaria asterigera, 

 Sars. In a surface sample taken in 61» 9.5' N. and 3« 50.5' 

 E., May 12th, 1896, a little sea-star was found the appearance 

 of which corresponds well with the small ones on the bipinnaria 

 mentioned. It seems to have been made evident that b. asterigera 

 is the larva of luidia sarsii, whose spawning time must consequently 

 be very irregular as Mr. M. Saes has observed the said larvaj in 

 May, Messrs. Koben and Danielsen in the months September- 

 October, and I in February. 



Spadella (sagitta) hamata, Mobius. 

 This chsetognath I have taken many times, both in the fjords 

 near Bergen and in Lofoten, but never in shallow water. Mr. 

 Mobius*) mentions it from the Korsfjord in depths of from 135 to 

 337 fathoms, while Aueivillius, during the Swedish Scagerrack 

 Expedition of 1893—94, notes it from 0—100 m. in water whose 

 saltness was 22.31 — 35.05 "/oo, and temperature 2».85— 17».3 C. 

 Mr. AuBiviLLirs**) gives the length at 18 mm. for specimens from 

 the Swedish Scagerrack coast. The largest ones I have till now 

 measured were 24 mm. (Feb. 23th, 1897; between Barci and Lo- 

 dingen. — 190 m.). Mr. Steodtmann states that s. ham.ata may 

 reach the length of 3—4 cm., but such large individuals are pro- 

 bably only found in high arctic regions. I have the idea that s. 

 hamata at our coast is thriving best in water of 6"— 70 C., and 

 with a saltness of 34—35 7oo. In some places, as in the ()stnes- 

 fjord and at Sundero in Vesteraalen, I have observed chmtognata 

 also in the surface, but this has been another kind (s. bipunctata). 



Tomopteris septentrionalis, Stenstrup. 

 In "Videnskabelige Meddelelser fra den Natuihistoriske For- 

 ening i Kjobenhavn", 1849—50, p. IV, Mr. Stensteot states that 

 the Copenhagen Museum had received from dr. Rink a great num- 

 ber of specimens of this kind, in part taken a few miles off the 

 Norwegian coast, in part in the sea round the Orkneys and the 

 Faroe islands. Mr. Stessteup considered it different from the 

 form observed in the South Sea by Escrholtz (t. onisciformis). 

 In "Fiinfter Bericht der Kommission zur w. Unters. d. Deutsch. 

 Meere", Mr. Mobius (p. 117) has mentioned a form, t. helgolandica, 

 Greef, which in all probability is synonymous with t. septentrionalis. 

 Besides in other places, the German Expedition has also observed 

 the form mentioned in the neighbourhood of Lindesnes. Mr. G. 

 0. Saes has informed me that he has often met with tomopteris 



both in the Kristiania-fjord and along the whole West-coast as far 

 as Lofoten. In the many plancton samples that I have taken 

 during the last two years, this form has only occurred a single 

 time, namely Feb. 25th, 1897, in the Ofoten-fjord in a sample 

 from — 250 m. Further, dr. Appellof took a fine specimen in 

 the Bergen By-fjord in the summer 1894. It had a total length of 

 about 40 mm. 



Calanus finmarcliicus, Gunnerus. 

 Mr. GiESBEECHT has noticed that this is probably the first 

 marine pelagic copepod that has been described. That honour 

 belongs to the Norwegian bishop Johan Eenst Gunneeus (1718— 

 1773). The original name was monoculus fijimarchicus, and the 

 original description is found in "Let Kongebg Norske Videnskabs- 

 selskabs Skriftcr". This copepod seems to occur in the plancton 

 at our coast at any time of the year, at least the females, the 

 males on the contrary being rarer. Mr. Gibsbeecht in his "Mono- 

 graphie" gives the following measures for the female: 

 At Naples 2.7—2.9 mm. 



- Gibraltar 3.0 „ 



- Spitsbergen, the largest ones 4—4.5 „ 



The grown-up males are stated to vary between 2.35 — 3.2 mm. 

 I have undertaken a number of measurements of both sexes. 

 Feb. 23th, 1897; between Baro and Lodingen; 0—200 m. 

 9 3.7 mm. 

 d 3.6 „ 

 c^ 3.6 „ 

 Feb. 24th, 1897; off the mouth of the Tjeldsund; 0—200 m. 

 9 3.7 mm. 

 d- 3.3 „ 

 d 3.2 „ 

 July 1st, 1897; 15 geogr. miles north of Jan Mayn; m. 



9 5.0 mm. 

 Feb. 14th, 1898; Herhifjord near Bergen; 0—400 m. 

 9 3.0 mm. 

 d 3.4 „ 

 From this will be seen tliat even in the deep of the fjords 

 near Bergen the male may reach the length of 3.4 mm., while in 

 the arctic sea the female can reach a length of 5 ram. The upper 

 limit of variation is tlius somewhat extended. 



*) Jahresbericht der Commission zur wissentschaftl. Untersuch. d. Deutscli. 



M. II, III Jahrg., p. 158. 



**) Das Plankton des Baltischen Meeres, p. 37 (Bihang t. Kgl. S. Yet. 

 Akad. Handl. Band. 21, Stockholm 1896). 



Calanus hyperboreus, Krilyer. 



9 



Apart from the difference of size, the female of c. liyperhorcus 

 is easily distinguished from c. fimm. 9, the lateral corners of the 

 5th body-segment being pointed in the former, while they are 

 rounded off in the latter. Tlie arrangement of teeth on the basal 

 joint in the fifth pair of feet (fig. 28) also gives a good mark of 

 distinction. The interval of variation is stated by Giesbeecht to 

 be 6.9 — 9.6 mm. Having taken several specimens of the said form 

 both in Lofoten and in the Ofoten-fjord, I give here some measures- 



