58 



ANNELIDS. I. 



have to deal with small specimens that the difficulties commence; these are well known to every zoolo- 

 gist who has had to deal with a considerable material of the genus in question. Even 0rsted 

 himself writes in his Amiulatorum Danicorum conspectus p. 31. "Difficillimum stepe est eharacteres 

 specificos firmos inter species hujus genesis statuere" and Levi use 11 completely gave up as to the 

 northern forms, and united them all in one species, Ph. maculata L. 



As to the differences between Phyllodoce groenlandica 0rsted and Ph. maculata L. I shall 

 first emphasize that, while Ph. maculata is a small or at any rate rather small species which only reaches 

 a length of a few centimetres, the Phyllodoce groenlandica is a large species, probably the largest 

 northern species, reaching a length of nearly half a meter. Orsted indicates in his description a 

 maximum measure of 10 to 11 Danish inches. The largest specimen at my disposal measures 450 mm. 

 in length, and several others reach a length of 400 mm. The colour of these animals is commonly 

 greyish brown, so that the body itself is almost grey with a bluish hue, while the elytra are slightly 

 chocolate-brown or earth-brown. In single specimens the body itself is dark brown, and the colour of 



the scales paler. In others the body is bluish, and in such specimens I 

 have seen the dorsal leaves very dark, almost black. 



In the species under consideration the cephalic lobe is relatively smaller 



than in Phyllodoce maculata; it is somewhat broader in shape and the 



nuchal flabs more prominent; the dorsal cirri in Phyllodoce groenlandica 



are almost rectangular in shape, with the angles rounded, in Ph. maculata 



they are broadly ovoid terminating in a blunt tip. The ventral cirri in 



Ph. groenlandica end in a tip, in Ph. maculata the same are ovoid 



and do not terminate in a tip. In giving prominence to these differences 



I shall note that the cirri here mentioned originate (fig. 24) from about 



fig- 2 4- the middle of the body. The differences pointed out do not hold good 



when f. i. cirri are taken near the head in one specimen and near the tail in another; in a single 



specimen the cirri vary considerably according to their place in the body. 



The bristles are much alike in the two species; rather constant appears to me the difference 

 consisting in the fact that the end-blade is relatively longer, terminating in a longer hairy tip, in 

 Phyllodoce groenlandica than in Ph. maculata Unfortunately it appears impossible to employ the supply 

 of papillae in the pharynx to distinguish the two specimens under consideration. The proximal half 

 of the protruded pharynx is in both forms beset with papillse, arranged in six regular longitudinal 

 rows on each side. The form of the papillae is rather uniform in both species, namely ovoid and 

 somewhat flattened. 



Finally I shall remark that, while the colour in Phyllodoce groenlandica is rather uniform, the 

 Ph. maculata is strongly spotted, a fact which caused O. F. Midler to give it the name of maculata. 

 As a rule, it can be said that it is not difficult to separate the two species from each other, 

 especially when it is a question of full grown individuals. Meanwhile specimens can be met with 

 differing from the usual aspect, and among the material I have had under examination some which I 

 must deal with more in detail. 



Two specimens are present originating from "Store Hellefiskebanke" in West Greenland, off the 



