collected in the Sea of Spitzhergen. 59 



thinner proboscis is 15 millims. long. The smooth surface is 

 of a pearl-grey colour, with faint yellowish pigment-spots. 

 On the intestine I found three suspensors, whilst Keferstein 

 gives only one, and moreover the convolutions of the intestine 

 were twisted round one of the retractors — a character which is 

 probably to be regarded as a malformation caused by disturb- 

 ance of development. The species was previously known only 

 from Greenland. 



Halicryjptus spmulosus (V. Sieb.). Storfjord. 



The occurrence of this animal in the sea of Spitzbergen 

 was made known by a note of Keferstein's (Zeitschr. fur wiss. 

 Zool. 1865, XV. p. 441), who saw large specimens, collected 

 by Malmgren, in the Museum of Stockholm. As, to my know- 

 ledge, the worm has never been found in the North Sea ; but 

 its occurrence beyond the Arctic Ocean is limited to the Baltic 

 (Reval, Riga, Danzig, Hiddensee, and the harbour of Kiel), 

 there appears to be a similar condition for its distribution as 

 for that of Antinoe Sarsii, except that the Halicryptus occurs 

 also in the southern part of the Baltic, where Antinoe Sarsii 

 is wanting. That Halicryptus is consequently to be regarded 

 as an originally widely diffused inhabitant of the Northern 

 Ocean, which has been displaced from the Norwegian coast, 

 since the glacial period, by the invasion of the gulf- stream, 

 but has maintained its existence in the Baltic, may probably 

 be affirmed, although its distribution cannot be accepted as a 

 proof that the icy sea was formerly united with the Baltic 

 through the White Sea and Ladoga Bay ; for as it occurs also 

 in the southern part of the Baltic, it cannot be denied that the 

 combination of Baltic and Spitzbergen forms may have taken 

 place, in the glacial period, through water-passages, such as 

 the Sound and the Belt, which now unite the North Sea and 

 the Baltic. But this renders more remarkable the peculiar 

 distribution of Antinoe Sarsii, the Baltic forms of which, as 

 above mentioned, are so shut off in the Baltic that their dif- 

 fusion cannot have taken place in this way. Sanger has 

 stated (according to Leuckart's Report on the Progress of the 

 Natural History of the Lower Animals in 1868-69, in Arch, 

 fur Naturg, xxxv. part 2, p. 281) that the Halicrypli of the 

 Bay of Kiel and those occurring near Danzig and Beval ex- 

 hibit differences in the oesophageal teeth, the Kiel variety 

 having 8 series of oesophageal teeth each with 8-12 lateral 

 teeth, and the Danzig variety only 5 series of oesophageal 

 teeth, each with 4-8 lateral teeth. We do not know whether 

 differences in the general size of the animals are combined 

 with this. It would be interesting to ascertain whether local 

 races have been developed in this case, and in what propor- 



