NICOMACHE MACULATA. 303 



1896. Nicomache lumbricalis, Benham. Camb. Nat. Hist., vol. ii, p. 332. 



1911. „ metadata, Arwidsson. Proc. Roy. Irish Acad., vol. xxix, p. 209, pi. xviii, figs. 13 — 19, 



and pi. xix, figs. 27—30. 



1912. „ „ Mcintosh. Ann. Nat. Hist., ser. 8, vol. xi, p. 86. 



1914. „ „ Southern. Proc. Roy. Irish Acad., vol. xxxi, no. 47, p. 134. 



Habitat. — Abundant between tide-marks at the Bast Rocks, St. Andrews, in tubes of 

 sand in fissures of the rocks; under stones near Paible, North Uist, near low-water mark; 

 very common at Herm, near the harbour, where the sand is so crowded with their tubes 

 as to be almost bristled with them, and thus affording a tempting feeding-ground for 

 waders and other sea birds. Small examples occur in tubes of mud, shell-fragments, sand- 

 grains, and secretions on the outer and inner surfaces of valves of Pectan opercularis in 

 Shetland (J. Gr. Jeffreys). In six to eight fathoms in the West Voe of Burra, Shetland, 

 in long tubes of secretion, sand-grains, and minute shell-fragments, the tube ending 

 posteriorly in a blunt point. At St. Andrews it is common in fissures of the shale 

 inhabited by Pholas, in tubes of sand which may form coherent sandy masses. The 

 inner lining of the tube is dark brownish or madder brown, whilst the sand-grains in some 

 cases are ochreous. It is equally common in Ireland on both eastern and western shores 

 (Arwidsson, Southern). It is probably the species mentioned by Grrube at St. Vaast, 

 and may be found extensively distributed elsewhere on the European shores. 



De St. Joseph (1906) describes the segmental organs as four pairs, in segments 4 to 

 8, and attached near the ventral nerve-cord on the one hand and the body-wall on the 

 other. They are the organs of Bojanus of Cosmovici. The axis is occupied by a ciliated 

 canal, which opens on a papilla at the extremity of a torus near the ventral median line. 



The anterior end (Plate XCII, figs. 5 and 5 a) is somewhat bluntly truncated, rounded 

 in the living form, but in the preserved condition it presents inferiorly a somewhat shovel- 

 shaped short projection. Viewed from the front in the preparations the pigmented peri- 

 stomial segment terminates dorsally rather abruptly, the pale cephalic keel passing 

 downward and forward and being lost on the symmetrically expanded snout. The nuchal 

 grooves occupy each side of the ridge and curve outward at their anterior end, whilst the 

 madder-brown pigment in its symmetrical disposition often mimics an eye on each side. 

 The minute eye-specks are situated in a row on either side of the anterior border, 

 between the tip of the nuchal groove and the ventral edge. The fusion of the pro- and 

 peristomal segments is close, and both would seem to take part in the formation of the 

 anterior process, for the symmetrical furrows from the mouth occur on its under surface. 

 The mouth forms a transverse furrow posteriorly, whilst in front a median and two lateral 

 furrows pass forward to the snout. In examples in which the head has been recently 

 regenerated the parts are pale, the anterior process or prow is shorter and has a median 

 dimple. 



In contrast with the foregoing the snout of the northern N. lumbricalis is less pro- 

 duced anteriorly, a condition very evident in a lateral view. Moreover, antero-posteriorly 

 N. lumbricalis has a more rounded and less elevated crown, whereas in N. maculata the 

 crown is higher and narrower. There is no specialisation of pigment as in A. maculata 

 in separate touches, though the upper or dorsal half is reddish-brown and the lower 



1 < Ann. Sc. nat./ 9 e ser., t. iii, p. 173. 



