11 



ANNELIDS. I. 



Drieschia melanostoma n. sp. 



PI. III. fig. 2. 

 Locality : 



Si°oo' N. L. n°43' W. L. 1350 — 840111. W. Young-fish trawl. South West of Ireland. 



Among a lot of specimens of Harmothoe Uubr ecAti M.c. In tosh, the author found four animals 

 of an aspect differing somewhat from the rest. They were more slender in shape, they were composed 

 of fewer segments, and the parapods were lower and somewhat longer. In one respect they agreed 

 well with the others, namely in the colour; they were milky white, just the colour assumed by transparent, 

 pelagic animals when preserved in spirit; the proboscis was deeply dark-violet as with all the worms in 

 the same glass. Only one specimen had the pharynx protruded, but on account of its dark colour it 

 was plainly seen through the skin. A closer examination showed that the four specimens in mention 

 not only belonged to another species but also were generically different from H. Hubrechti. With some 

 hesitation I refer them to the genus Drieschia, established by Michaelsen on a pelagic Polynoid, 

 taken near Ceylon. They seem to me to be closer related with a form described by Moore from 

 Woods Hole, to which he has given the name of Drieschia fellucida^ but at any rate they are specifically 

 different also from this species. 



Michaelsen characterizes his genus Drieschia in the following manner: "Korper kurz, aus dem 

 Kopflappen und 28 Segmenten zusammengesetzt; Kopflappen und Anhange desselbeu wie bei der 



Gattung Lepidonotus\ 13 Elytrenpaare an den Segmenten 2, 4, 5, 7 21, 23 u. 26; Ruder einastig, 



mit eiuer Acicula und zweierlei Borsteu; die Borsten der ersten Form sehr dunn, lang-haarformig; die 

 Borsten der zweiten Form dicker, und uuterhalb des ausseren, spitzeu Endes erweitert und ornamentiert." 



Already the species described by Moore necessitates alterations in the quoted diagnosis, in as much 

 as the number of segments in this species is only 25. The form at my disposal demands a further 

 extension of the frame. In the first place the number of segments is 30, consequently greater than in 

 both of the formerly described species. In the second place is found in the parapod a notopodial 

 acicle, though the notopodial branch is for the rest rudimental and devoid of seta;. 



The generic diagnosis will then be as follows: 



The body short, consisting of a small number of segments viz. c. 25 — 30. Cephalic lobe and its 

 appendages as in Lepidonohts. Scales on the following segments: 2, 4, 5, 7 ... 21 ... 23 and 26. In 

 the foot the notopodial branch is suppressed or rudimental. Two sorts of bristles in the neuropodial 

 branch, partly very thin or capillary, partly thicker with more or less broad end-blade. Sometimes are 

 found a few which are in shape transitional between the two sorts. 



The last remark dealing with the bristles is added because a sharply pronounced difference 

 between the thinner and thicker setae is found in neither of the two Atlantic species, such as is the case 

 in the species described by Michaelsen; specially the thin, capillary ones are not nearly so thin as the 

 corresponding ones in the form from Ceylon; in this they are not only capillary in shape but they seem 

 to be flexible as the most delicate hair. This is not the case in the Atlantic forms, specially not in the 

 species examined by me. And in the Atlantic forms the bristles in question are thicker in their proxi- 



