43 



Paa Bagkropjjeu tindes i Bugkuudeu 2 Slags Haarborster, 

 lange, tyude og kortere, tykkere med smalt bræmmet Spids. 

 Hageborsterne luiiseriale. aviculære (T. VII. Fig. 27). 

 Brauchienie 10 — 12 paa hver Side med lange Radioler 

 lige til Si)idscn. 



Protula arctica, n. sp. 



Stat. 51. 



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

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

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

 uden Branchier l..oCtm. langt, Branchierne 1 Ctm. lange; 

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

 kroppen bestaar af 7 Segmenter; Kraven opret med et 

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

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

 imembranen. hvis tvende Bræmme ligge over hiuanden og 

 dække hele Rygfladeu af Forkroppen. Paa Siderne skinner 

 den skældannende Kjertel gennem Huden. Paa første Seg- 

 ment findes almindelige Haarborster med en lang. krum- 

 met Spids og nedenfor denne en kort. temmehg bred, 

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

 lindes ogsaa Hageborstetori. De kapillære Børster ere 

 talrige i hvert Led og korte, nedenfor den lauge Spids 

 forsynede med en temmelig lang, smal, fint tandet Bræm 

 (T. VII, Fig. 32). Hageborsterne have 6 Tænder, af 

 hvilke den nederste er dobbelt saa tyk som de ovrige 

 (T. VII. Fig. 3(J). Bagkroppens samtlige Led ere for- 

 synede med dorsalt stiUede Hageborster og ventrale Haar- 

 borstebundter. Hageborsterne 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 foi-reste Del temmelig korte, paa 

 de sidste ca. 3U Led derimod meget lange. Branchierne 

 ere besatte med temmelig lange Radioler. have en kort 

 nogen Spids, nedenfor hvilken de forste Radioler ere korte, 

 tiltagende i Længde nedover. Branchierne. 18 — 20 paa 

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

 med en Begyudelse til Spii'aldreiuing. 



series having a long slender point protending trorfi a long 

 arcuate stem (PI. VII, fig. 2(3, a); those in the second, 

 which are avicular, likewise issuing from a long stem 

 (tig. 20. h). On the posterior portion of the body, 2 kinds 

 of capillary seta" in the ventral pi'otuberance, the one long 

 and slender, the other comparatively short and thick. 

 with broad-belted points. The unciui uniserial. avicular 

 (PI. VII. tig. 27). From ]0 to 12 branchiæ on either 

 side, with long radiolæ 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 1" 

 long; thickness about l'"'". Body round, slightly cemprejM'd; 

 the anterior portion consisting of 7 segments; the collar 

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

 (PI. VII, tig. 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 has only the usual capilli- 

 form setæ with long arcuate points, below which is seen 

 a short, comparatively broad dentated border (PI. VII, 

 fig. 31). On the G following segments also uncini. The 

 capilliform setæ. numerous on each segment, are short, 

 and have below the elongate point a comparatively long, 

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

 setæ with 6 teeth, the lowerinost twice as thick as the 

 others (PI. VII. fig. 30). The segments on the posterior 

 portion of the body all furnished with ungueal setæ. dorsally 

 situated, and with fascicles of ventral cajiilliform setæ. 

 The ungueal setæ are similar in form to those on the 

 anterior part of the body, but not more than al)out half 

 as long. The capilliform setæ perfectly smooth (PI. VII, 

 fig. 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 18 to 20 on either side, 

 attached to a free lamella, rise anteriorly, commencing 

 with a spiral twist. 



6* 



