274 On Annelida Polycha'ta from the North Sea d:c. 



"The dorsal surface of tlie segments shows under the micro- 

 scope tnmsverse striae, somewhat irregularly arranged." 

 The proboscis is not extruded, so no comparison with M. per- 

 armata can be made. The alimentary canal is almost straight 

 and uniform for the first seven setigerous segments, and then 

 it assumes a sacculated appearance posteriorly. 



The foot in this specimen resembles that of M. perarmata 

 in being uniramous, having the long cirrus dorsally with a 

 spine in the ceratophore, and a very bluntly conical setigerous 

 region, with a small pai)illa3 supported by two fairly stout 

 spines, and carrying a fan-shaped tuft of translucent Ijristles. 

 Tiie articulations of the cirrus, however, are not so large as, 

 but are more numerous than, those of Af. perarmata. Most 

 of the bristles have slightly curved shafts, which are striated 

 and have a bevelled appearance at the tip, the distal end of 

 wliich is somewhat blunt, and in several of those whose 

 terminal pieces are deeply serrated is slightly cleft (see 

 fig. 2). Tiie terminal pieces vary from medium to long. 

 In all the tip is liooked, and a secondary process is present 

 beneath. Tlie tip of the bristles in M. perarmata, on the 

 other hand, is not so distitict, for it is only in the shorter 

 forms that tlie minute structure is distinguishable. The 

 edges of tiie blades, however, present great differences. In 

 M. perarmata the edge is minutely serrated and the serrations 

 are the same for every bristle (see fig. 3) ; but in this form 

 the serrations are very large and, in several of the larger 

 blades, resemble the deep serrations in the blade of Gastalia 

 fusca (see figs. 1 & 2). Thus two distinct forms of serration 

 are present. 



In many respects the animal agrees with M. perarmata, 

 but the distal end of the sjiafts and the serrations of the 

 blades are so divergent and diagnostic, that one is compelled 

 to consider it as a new species, allied, however, to M. per- 

 armata. The specimen is not mature. Moreover, it is an 

 interesting feature that the distribution of the genus has 

 been extended northward, for not a single example of At. per- 

 armata has been found, up to date, north of Plymouth. 



Bihliograplv/. 



IIkinrn. 1011. ' Dio Nephthydeeii unci Lycoruloon tier Nord- nnd 



Ostseo.' 

 IzUKA. 1912. 'The ICrrantiato Polychirta of Japan.' 

 Malmgubn, 18Go. ' Nordi.ska Haf.s-.\nniilater.' Stockholm. 

 Marion et BomuasiCY. 187o. "Annelido.s dii (Jolfo de Mar.stiille." 



Annales des Science.s Naturelles, .sixioino serip, toiiio ii. 

 M'l.NTosu. 1874. TraiH. Zool. 8oc. vol. ix. part 7. "On Eritisli 



Annelida." 



