18 THÉEL, NORTHERN AND ARCTIC TNVERTEBRATES. II. PRIAPULIDS. ECHIURIDS ETC. 



Gotland (Théel 1875, Lenz 1878, Fischer 1895 etc). I myself, at least, have never 

 had the opportunity of examining a specimen dredged from a locality nortli of the 

 58° 6' latitude. 



Furthermore, it is by no means rare at the coasts of Denmark (Levinsen 1883 

 & 1903) and of the British Isles (Forbes 1841, Ehlers 1861, MTntosh 1875 etc). 

 Finally Möbius (1875) reports it from Wangeroog, one of the east Friesich Islands, 

 and according to Ehlers it is also found at the coast of Belgium. 



From what hås been said above, it becomes evident that the Priapus caudatus 

 is dispersed all över the North-Atlantic Ocean, though it probably may not occur 

 South of the British Channel. 



But in other respects too the studies of the distribution of this species reveal 

 matters of very great interest. Priapulus caudatus, or at least a form very nearly 

 related to it, appears to have been obtained at several places in the Antarctic Sea. 

 Consequently the important question arises whether we have to do with a true 

 bipolär species. 



In 1888 de Guerne reports a Priapulus from the Antarctic regions (Orange Bay, 

 Strait of Magellan and Falkland Islands), which he named Pr. tuberculato-spinosus 

 and which, according to him, »représente dans le Sud Pr. caudatus des mers du Nord». 



Låter in 1889 Michaelsen states that he has had an opportunity of investi- 

 gating two specimens of a Priapulus from the South Georgia, presenting such a striking 

 resemblance to the northern Pr. caudatus that he was unable to distinguish them 

 as separate species. He named the antarctic form Priapulus caudatus Lam. var. ant- 

 arcticus and supposed it to be identical with the species of de Guerne. 



In 1890 Pfeffer writes: »Der Priapulus von Sud-Georgien ist artlich von der 

 nordlischen Form nicht zu unterscheiden». 



In 1902 Shipley reports it from Cape Adare and writes: »I follow Fischer in 

 regarding these Antarctic forms as belonging to the species P. caudatus Lam.». 

 Finally Skorikow (1902) tells us that he has examined the true P. caudatus var. ant- 

 arcticus of Michaelsen brought home from several localities in the Arctic Sea. He 

 writes: »Ans den oben gegebenen vorläufigen Angaben geht also, wie mir scheint, die 

 nicht uninteressante Thatsache hervor, dass die friiher fiir rem antarktisch angesehene 

 Varietät Pr. caudatus var. antarcticus, bipolär zu sein scheint und auf der nördlichen 

 Erdkugel auf Circumpolarität Anspruch erheben darf». 



If we take for granted the correctness of all these statements the distribution 

 of Priapulus caudatus (Lam.) »is a striking case of what is termed the phenomenon 

 of bipolarity». 



Priapulus bicaudatus Danielssen 1868. 



I'l. I. figs. 3t-6, l'l. II. tigs. 9—10. 



Priapulus bicaudatus Théel 1875. Horst 1882. 

 Priapulopsis typica Koren and Danielssen 1875. 

 Priaptrfoides typicus Koren and Danielssen 1877 & 1881. 



