200 MICROTIA PURPUREA. 



species. Dalyell observed that his specimens [Gordius fasciatus spini/er) had a tendency to rup- 

 ture at the white belts. Moreover, his examples reproduced bodies to the anterior regions, but no 

 heads on the posterior fragments, though he did not doubt that regeneration would ensue in every 

 case under more favourable circumstances. His G.fragilis spinifer is probably a specimen of this 

 species uniformly tinted, and its subsequent fracture into many pieces is corroborative of this view. 

 I am in doubt, however, whether his G. viridis spini/er (op. cit., p. 78, PI. XI, f. 1) is a distinct 

 form or only a variety of this or the succeeding species. 



The MecMia annulata of Grube, and the M. Kneriioi Diesing, are closely allied to the fore- 

 going. The absence of the caudal process in the former may have been accidental, while, as 

 regards the latter, Prof. Grube may be wrong in supposing such only a reproduced tail. 



3. Micrura purpurea, BalyelL Plate VII, fig. 3. 



Specific character.— Eyeless. A bright yellow patch at the tip of the snout. Body of a 

 uniform rich dark brown colour. 



Synonyms. 

 1853. Gordius purpureus spinifer, Dalyell. Pow. Creat., vol. ii, p. 78, pi. 11, f. 2 — 4. 

 1858. Micrura purpurea, J. Muller. Archiv, p. 300. 

 1862. „ „ Diesing. Revis. der Turbell., p. 260. 



1865. Stylus purpureus, Johnston. Catalogue Brit. Mus., pp. 24 and 293. 



1868. „ „ Mcintosh. Ann. Nat. Hist., 4th ser., vol. ii, p. 293. 



1869, Micrura purpurea, Ibid. Trans. Roy. Soc. Edinb., vol. xxv, pt. ii, p. 374, &c. 



Habitat. — In fissures of rocks near low water, and between the valves of empty shells, or 

 other crevices of the debris from the coralline ground on the east coast of Scotland. It seems to 

 be generally diffused, and occurs of large size off the Shetland Islands. 



Body. — Five to eight inches in length, flattened, slightly narrowed behind the head, and 

 gradually tapered towards the rather blunt tail, from which the styliform process arises. 



Colour. — Rich dark brown with a purplish lustre on the dorsum. The tip of the snout is pale, 

 and immediately behind is a well-defined crescentic granular yellow patch. The convexity of the 

 latter is directed forward. In some specimens the anterior margin of the patch only is yellow, 

 while the rest is yellowish white or pure white. There is a slight reddish hue at the ganglionic 

 region. The styliform process is pale brown. The ventral surface is very slightly paler than the 

 dorsal, and from the translucency of the snout the yellow pigment-patch on the upper surface 

 shines through. 



Head. — With a truncate anterior margin which is also broad, so that it has a peculiar spade- 

 shaped appearance, slightly wider than the succeeding portion of the body, and with three papillae 

 in front, a central and two lateral, the latter being small and inconspicuous. The lateral 

 fissures are deep and well marked, the bottom tinted red posteriorly, and having anteriorly 

 some yellowish grains continued from the pigment-patch of the snout. There is no trace of 

 eye-specks, 



Micrura purpurea appears for the most part to be a deep-water species. In regard to 



