18 ARKIV FÖR ZOOLOGI. ba:n-d 7. N:0 5. 



Plate I.^ 



Description of tlie Figures of Arenicola loveni Kixberg. 



Fig. 1. The prostomium of the type specimen. Dorsal aspect: X. Gr. 

 Xuclial groove. XIO. For description, see p. 5. 



Fig. 2. The posterior end of the body and the first three tail segments 

 of the type specimen, seen from the right side, showing: — a 

 portion of the nineteenth segment, namely, the nineteenth chae- 

 tigerous annulus, ^Yith its neuropodium (Xr.^^j, notopodiuni 

 (X. ^^) and gill (Br. ^^). and the followingring; the extra, twen- 

 tieth, segment and notopodium (X.-^) which this specimen 

 possesses; the pit (P.), possibly sensory. X 5. For further 

 description, see p. 6. 



Fig. 3. Distal third of one of the shorter notopodial setae from a 

 Saldanha specimen, showing the »teeth», the transverse stria- 

 tion and the lamina. X 90. A portion, from the part mark- 

 ed + , is seen highly magnified in Fig. 4. 



Fig. 4. A portion of a notopodial seta, showing the toothed crests 

 or »Sägeblätter». X 1000. For descriptions of Figs. 3 and 

 4, see pp. 9 and 10. 



Fig. 5. Two neuropodial crotchets, A from the type specimen, B 

 from a Saldanha specimen. X 110. For description, see p. 10. 



Fig. 6. Two adjacent crotcliets from a Saldanha specimen, the left 

 one is abnormally slender (see p. 10). X 110. 



Fig. 7. The anterior portion of the type specimen, as far back as 

 the sixth chaetigerous segment, opened by an incision along 

 the mid-dorsal line. The figure, Avhich is natural size, shows: 

 — the pharynx (Ph.) protruded, the prostomium (Pr.) and its 

 retractor muscles, the three septa (S.^, S.^, S.^). The first 

 septum is puUed backwards, it is pierced by some of the 

 retractors (Ph. R.) of the pharynx, and bears the two enor- 

 mous, muscular, septal pouches (S. P.). The second septum 

 is perforated by two apertures — one right and one left of 

 the oesophagus — to permit the passage of the septal pouches. 

 Close behind the third septum are the oesophageal glands 

 (CE. Gl.) and the two hearts (H.) Avhich are dilated, the 

 right one fully. The first (Xph. ^) and second pairs of ne- 

 phridia are shown. D. V. Dorsal blood vessel, M. Ob. Ob- 



^ The cost of the original dravvings for this Plate has been defrayed 

 by the Earl of Moraj^ Endowment of the University of Edinburgh. 



