380 



LUMBRICONEREIS IMPATIENS 



1903. Lumbriconereis assimilis, Mcintosh. Ann. Nat. Hist., ser. 7, vol. xi, p. 561. 

 ,, „ „ (near), idem. Ibid., vol. xii, p. 158. 



1904. „ impatient, Allen. Journ. M. B. A., N.S., vol. vii, p. 226. 

 1906. „ „ De St. Joseph. Ann. Sc. nat., 9 e ser., t. iii, p. 161. 



Habitat. — Stomach of flounder, St. Andrews, and from the deeper water of the Bay 

 (E. M.). Dredged twenty-five miles off North Unst, Shetland, in ninety fathoms, by Dr. 

 Grwyn Jeffreys in July, 1868 ; Nymph Bank, South-west Ireland, in two and a half 

 fathoms, Royal Irish Academy's Expedition, 1886. In the centre of tubes of Panthalis 

 CErstedl, in fifty to seventy fathoms, west of Peel, Isle of Man (Herdman). Plymouth 

 (Allen). 



Shores of France, at Banyuls, in crevices of corallines (Pruvot). Naples and the 

 Mediterranean. 



Fig. 78. — Transverse section through a ripe female of Lumbriconereis impaiiens, the ccelom being occupied by- 

 masses of ova. 



Head forming a blunt cone as usual in the group, two nuchal organs with vibratile 

 cilia occurring posteriorly. 



Body up to 50 cm. (De St. Joseph) and o mm. in diameter, the first segment broader 

 than the second, and with numerous rings of nearly equal breadth. The feet generally 

 do not offer diagnostic features in a superficial view, though the bristles are somewhat 

 longer. Delle Chiaje describes it as reddish-brown with fine iridescence, and very fragile, 

 while De St. Joseph gives it a pale rose colour. The segments number between three and 

 four hundred in a large example. Posteriorly it ends in four anal cirri — two dorsal and two 

 ventral. The great development of the dorsal and ventral longitudinal muscles and the 

 position of the nerve-cords are well seen in this species (Fig. 78). 



The dental apparatus (Plate LXV, figs. 8 and 8 a) presents a pair of strong maxilla?, 

 the curves of which keep to the horizontal, and end posteriorly in a pointed lozenge-shaped 

 process. The great dental plates have each four teeth. The adjoining right anterior 

 plate has three small teeth, whereas the corresponding plate on the left has only an 

 unbroken edge. The other plate has a single tooth. An accessory horny patch and a 

 curved band toward the great dental plates complete the upper system. The conformation 



