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PROCEEDINGS OF THE NATIONAL MUSEUM. 



VOL. 39. 



large or moderately large, lateral lobes in the form of a V, the limbs 

 of uniform width, not dilated anteriorly, though they may be bent 

 (figs. 7, 8) ; neuropodia similar to those of A. claparedii; six pairs 

 of nephridia, wliich open on the fourth to the ninth segments; several 

 (6 to 15) pairs of oesophageal glands, the anterior pair long and 

 slender, the others smaller and more or less pear-shaped ; no pouches 

 on the first septum; a pair of large statocysts in the peristomium, 

 wliich open to the exterior; statohths numerous, spherical or rounded 

 secreted chitinoid bodies. 



Fig. 7.— a. assimilis, anterior end, dorsal 

 aspect, of specimen from uschuaia. the 

 prostomium is in a state of normal exten- 

 SION. For LETTERING SEE FIG. 8. X6. 



Fig. 8.— a. assimilis, var. affinis, anterior 

 end, dorsal aspect, of specimen from the 

 falkland islands. the prostomium is pro- 

 truded to its fullest extent. x6. i, lat- 

 eral lobe of prostomium; m, median lobe; 



A'l, FIRST NOTOPODIUM; P, MEDIAN POSTERIOR 

 PORTION OF PROSTOMIUM; PB, PHARTNX. 



ARENICOLA ASSEVirLIS, var. AFFINIS Ashworth. 



Nineteen chsetigerous segments; thirteen pairs of gills, the first, 

 which is liable to reduction, on the seventh segment. Statoliths 

 numerous, consisting of either foreign bodies, such as quartz grains, 

 or of rounded secreted chitinoid bodies. Other characters as given 

 above for A. assimilis Ehlers. 



A. assimilis has been recorded from — 



California.a E. Ehlers, Polychaeten, p. 104, in Hamburger Magalhaensische 

 Sammelreise, Hamburg, 1897. 



Punta Arenas (Strait of Magellan), Lapataia Nueva (Beagle Channel) and Uschuaia 

 (Tierra del Fuego). E. Ehlers, Polychaeten, p. 104, in Hamburger Magalhaensische 

 Sammelreise, Hamburg, 1897; also Festschr. K. Ges. Wiss. Gottingen, 1901, p. 178. 



Susanna Cove (Strait of Magellan).b E. Ehlers, Polychaeten, p. 104, in Ham- 

 burger Magalhaensische Sammelreise, Hamburg, 1901; also Zool. Jahrb., Suppl. 5, 

 Fauna Chilensis, vol. 2, pp. 265, 269, 1901. 



South Georgia. E. Ehlers, Polychaeten, p. 104, in Hamburger Magalhaensische 

 Sammelreise, Hamburg, 1897; also Festschr. K. Ges. Wiss. Gottingen, 1901, p. 178. 



« Transfer to A. claparedii, see p. 19. 



b Transfer to var. affinis, see p. 19. 



