422 .1. A'. Vi'fril} — Marine A^emcrf.eans of Neio I'Jni/hnKl, etc. 



partially contracted ; nor could they be referred to any other Green- 

 land species. 



The lateral slits of the head of this species are spoken of on p, 325 

 of the Fauna Gnpnlandica, and are also distinctly shown in the 

 figures. Fabricius speaks of his virklis as common on the shores of 

 Greenland among the roots of alg;e. I have personallj^ examined 

 good specimens of this species recently taken on the coast of Green- 

 land in the same situations. There can l)e no doubt of their identity 

 with the true virklis. Therefore there is not the slightest reason 

 why his characteristic name should not be used, in preference to 

 Gessereyisis* of much later date. 



Although the latter name has been adopted by many recent writers 

 on European nemerteans, the ordinaiy rules of priority, as well as 

 justice to the very meritorious author of the Fauna Grwnlandica, 

 should compel a change in this rcs]>ect. 



Fabricius and Midler, in the same works, described another Green- 

 land form under the name of rubra. I am of the opinion that this 

 was simply the red variety of L. viridis, for the two varieties occur 

 together everywhere on the northern coast of America. Levinsen, 

 however, has referred the rubra to L. sanguineus^ and has given the 

 latter as a Greenland species. If both species actually inhabit 

 Greenland his view may be correct, for there is nothing in the orig- 

 inal description to indicate that it belongs to one ratlun- than to 

 the other of these two species, if it really belonged to eithor.f 



Indeed these; two re))uted species arc so much alike that I am my- 

 self in doubt whether they arc really distinct. There is no special 

 diagnostic character given by Mcintosh unless it be the somewhat 

 narrower head in X. sanguineus. The sha])e of the head in this genus 

 is so changeable and variable that, in practice, little reliance can be 

 placed upon this as a diagnostic character. The ocelli are supj)osed 

 to differ slightly in size and number, but they also vary in both 

 forms. Hence it seems to me not improbable that a more extended 

 study of the variations will compel us to consider X. sanguineus 

 only a lighter red variety of L. viridis. In this article I have, how- 

 ever, followed most European writers in keeping them separate, 

 although I confess that with scores of living specimens of both 



* Levinsen, in his recent paper on the Turbellaria of Oreenland, also records tho 

 typical form, under the name of L. Gesserensis, as a native of that coast. 



f Fabricius mentions neither ocelli nor cephalic slits in this species. Therefore it 

 may not have been a Linens. The necessary rloubt concerning its true relations 

 should prevent the application of the name to any species. 



