43 



Paa Bagkroppen findes i Bugknuden 2 Slags Eaarbørster, 

 lange, tynde og kortere, tykkere med small bræmmel Spids. 

 Eagebørsteme uniseriale, aviculære (T. VII. Fig. 27). 

 Branchieme lo — 12 paa hver Side med lange Radioler 

 lige til Spidsen. 



Protula arctica. n. sp. 



Stat. 51. 



To Exemplarer, fra Stat. 40 to tomme Ror. Rorene 

 err hvide, af Kalk. forsynede med mere og mindre tyde- 

 ligt fremtrædende Tværstriber (T. VII, Fig. 28). Dyret 

 uden Brancbier 1.5 Otm. langt, Branchieme 1 Ctm. lange; 

 Tykkelsen ca. 1""". Kruppen er rund. lidt fladtrykt, For- 

 kroppen bestaar af 7 Segmenter: Kraven opret med et 

 dybt Indsnit fortil og et paa hver Side (T. VII, Fig. 29), 

 aaben bagtil, hvor den paa begge Sider gaar over i Bryst- 

 membranen, hvis tvende Bræmme ligge over binanden og 

 dække hele Rygtladen af Forkroppen. Paa Siderne skinner 

 den skældannende Kjertel gennem Huden. Paa første Seg- 

 ment tindes almindelige Haarborster med en lang. krum- 

 met Spids og nedenfor denne en kort. temmelig bred, 

 tandet Bræm (T. VII, Fig. 31). Paa de 6 følgende Led 

 tindes ogsaa Hagebørstetori. De kapillære Børster ere 

 talrige i hvert Led og korte, nedenfor den lange Spids 

 forsynede med en temmelig lang. smal. fint tandet Bræm 

 (T. VII. Fig. o-l). Hagebørsterne have ti Tænder, af 

 hvilke den nederste er dobbelt saa fyk som de øvrige 

 (T. VLT. Fig. 30). Bagkroppens samtlige Led ere for- 

 synede med dorsalt stillede Hagebørster og ventrale Haar- 

 børstebundter. Hagebørsterne have samme Form som de 

 paa Forkroppen, men ere kun omtrent halvt saa store 

 som disse. Haarbørsterne ere fuldkommen glatte (T. VII, 

 Fig. 33) og paa den forreste Del temmelig korte, paa 

 de sidste ca. 30 Led derimod meget lange. Branchieme 

 ere besatte med temmelig lange Radiolei'. have en kort 

 nogen Spids. nedenfor hvilken de første Radioler ere korte, 

 tiltagende i Længde nedover. Branchieme. 18 — 20 paa 

 hver Side. sidde paa et Blad. der hæver sig frit op fortil 

 med en Begyndelse til Spiraldreining. 



series having a long slender point protending from a long 

 arcuate stem (Pl. Vil, 6g. 26, a); those in the second. 

 which are avicular, likewise issuing from a long stem 

 (fig. 26, l>). On the posterior portion of the body, 2 kinds 

 of capillary seta' in the ventral protuberance, the one long 

 and slender, the other comparatively slunt and thick, 

 with broad-belted points. The uncini uniserial. avicular 

 (PI. VII, tig. 27). From 10 to 12 branchiæ on either 

 side, with long radiokc from the base to the point of 

 the upper extremity. 



Protula arctica. n. sp. 



Stat. 51. 



Two specimens-, from Station 40 two empty tubes. 

 The tubes, more or less distinctly marked with transverse 

 striæ. white, consisting of calcareous deposit (PI. VII. tig. 

 28). Length 1.5"" without the branchiæ, which are l cm 

 long; thickness about 1""". Body round, slightly cempressed; 

 the anterior portion consisting of 7 segments; the collar 

 erect, with a deep incision anteriorly, one on either side 

 (PI. VII, fig. 29); open posteriorly, where it coalesces on 

 both sides with the thoracic membrane; the two folds of 

 which lie one upon the other, covering the whole surface 

 of the back on the anterior portion of the body. On the 

 sides, the shell-producing gland is seen shining through the 

 integument. The 1st segment lias only the usual capilli- 

 form setæ with long arcuate points, below which is seen 

 a short, comparatively broad dentated border (PL VII, 

 fig. :J1). On the 6 following segments also uncini. The 

 capilliform seta», numerous on each segment, are short, 

 and have below the elongate point a comparatively long. 

 narrow, finely toothed border (PI. VII, fig. 32). The ungueal 

 seta? with 6 teeth, the lowermost twice as thick as the 

 others (PL VII. tig. 30). The segments on the posterior 

 portion of the body all furnished with ungueal setæ. dorsally 

 situated. and with fascicles of ventral capilliform setæ. 

 The ungueal setæ are similar in form to those on the 

 anterior part of the body, but not more than about half 

 as long. The capilliform setæ perfectly smooth (PL VII. 

 tig. 33). and on the anterior part of the body compara- 

 tively short: but on the terminal segments — about 30 — 

 they are. on the other hand, exceedingly long. The bran- 

 chiæ, studded with comparatively long radiolæ, have a 

 short, naked point: the first radiolæ. a. little below the 

 point, are short, the remainder increasing in length down- 

 wards. The branchiæ, from IS to 20 on either side, 

 attached to a free lamella, rise anteriorly, commencing 

 with a spiral twist. 



0* 



