MYRIAMDA PINNIGEKA. 231 



differentiated ; they had twenty segments. The eighth and ninth corresponded, and the 

 bifurcation of the palps had commenced. In the eleventh and twelfth the bifurcation of 

 the palps was marked, and the tentacles were present. They had twenty-three segments. 

 From the sixth to the twelfth bud there were four reddish-orange touches. In the 

 thirteenth and fourteenth the palps were completely bifurcate, the tentacles well 

 developed, and the eyes large. The fifteenth and last ripe stolon became detached under 

 observation. 



Foot. — In the nurse-stock (Plate LXXI, fig. 5) dorsally is a long ceratophore 

 rounded at the end. It bears the large flattened cirrus, the tissue of which is much 

 more lax than that of the basal process, and has pigment and glands. The cirrus forms 

 a long flattened blade, somewhat pointed at the tip, and having a central nerve of con- 

 siderable size, which gives off branches on its way to the tip. The inferior lobe has 

 superiorly a prominent papilla above the tips of the spines, which form a group. The 

 outline of the ventral border is nearly a semicircle, the swollen process inferiorly having 

 pigment and glandular tissue. The ventral bristles (Plate LXXIX, fig. 24) are rather 

 feeble, with elongated, slightly curved shafts dilated at the tip, the edges of the bevelled 

 region distally being minutely spinous, whilst the terminal piece is short and diminished 

 towards the bifid tip. As usual the points of the hooks are directed dorsally. 



In the bud a distinct papilla occurs between the ceratophore of the dorsal cirrus and 

 the base of the ventral lobe (Plate LXXI, fig. 6), from which a long tuft of swimming- 

 bristles (Plate LXXIX, fig. 24 a) projects. 



Reproduction. — The specimen procured on August 8th, in the Sound of Harris, carried 

 female buds, all with ova except the minute ones next the nurse-stock. The latter had 

 fully sixty segments, and there were ten buds. On the other hand, that procured in 

 Bressay Sound, Shetland, in July, carried male buds. 



In life the species is one of the most beautiful and graceful in the family. Its 

 brilliant orange spots, the translucency of its tissues, and its active movements as it trails 

 the long series of finely-coloured buds behind it, make it as striking as it is interesting. 



Montagu's Nereis pinnigera (1808) is a nurse-stock with a developing bud 

 posteriorly. He thought that at the posterior end it (the nurse-stock) " suddenly 

 decreases and becomes very small, as if that part had been newly formed ; a circum- 

 stance of no unreasonable conjecture, as it is well known that many of the Mollusca tribe 

 are capable of reproduction." The Nereis maculosa of the same author appears to be a 

 pelagic female bud of this species, 1 with swimming-bristles. Dr. Johnston made a 

 separate family for it (Amytiacese). In his manuscript volume of drawings (1808) in 

 the Linnsean Society, Montagu shows in Plate XVIII, fig. 2, under the name of Nereis 

 doridea, a female bud, and in fig. 4 the species itself (nurse-stock) with buds. 



The Myrianida longissima of Audouin and Edwards 2 is probably the same form. 



De St. Joseph describes the proventriculus in M. maculata, Claparede, as barrel- 

 shaped, with thirty-two rows of "oleaginous" dots, and occupying segments 13, 14, 



1 ' Trans. Linn. Soc./ xi, p. 21, Tab. hi, fig. 4, and also MS. vol. Drawings in the Linn. Soc., 

 Plate XXXV, fig. 4. 



2 ' 



Ann. Sc. Nat./ t. xxix, p. 240. 



