Fam. 3, Plate 26. 



EOLIS OLIVACEA, Alder and Hancock. 



E. flavido-alba, maculis albis; branchiis paucis, crassiusculis, cylindraceis, olivaceis, seriebus 6-8 

 digestis ; tentaculis lsevibus ; angulis anterioribus pedis brevibus, obtusis. 



Eolis olivacea, Aid. and Hanc. in Ann. Nat. Hist. v. 9, p. 35. 



Hab. Under stones between tide-marks, "Whitley and Cullercoats, Northumberland, not uncommon. 

 Whitburn, Durham. Rothesay Bay, Isle of Bute. 



Body about half an inch long, pale yellow or yellowish white, sprinkled with minute spots 

 of opake white. Dorsal tentacles rather short, nearly linear, obtuse, approximating at the 

 base, yellow speckled with white, and having a more or less distinct orange-red band in the 

 centre. Oral tentacles not so long as the dorsal ones, linear and obtuse, arising from the 

 upper surface of the lips. A streak of orange or rose-red extends on each side of the head 

 between the oral and dorsal tentacles, curving inwards, and is continued behind the latter a 

 short way down the back ; in some brilliantly coloured varieties there is a large sub-triangular 

 blotch of rose-red behind these on the centre of the back, and one on each side below the 

 dorsal tentacles. Branchiae rather few, thickish, elliptic-oblong, nearly cylindrical, of a 

 yellowish olive-brown, with numerous belts composed of granulated spots of dark olive, 

 sometimes indistinct. The apices pale ; the whole of the external surface covered with 

 patches composed of opaque whitish spots. The branchise are set along the sides in 6 to 8 

 rows of 3 or 4 papillae each : their size is nearly equal throughout. Foot watery white, 

 tapering to a fine point behind ; the anterior extremity widened and rounded. Eyes small, 

 placed close behind the dorsal tentacles. 



We know of no species with which this can be readily confounded. It is subject to some 

 slight variation in colour. Sometimes a specimen is found with the branchise of a richer hue, 

 approaching to reddish brown, and sometimes of a much darker or lighter tint, but the modest 

 olive generally prevails. In a specimen found in Rothesay Bay, the papilla? showed indications 

 of a brown ring at the apex. The spawn, which is deposited in the months of May and June, 

 forms a broad semicircular coil, attached to the under sides of stones. In the simple form of 

 the spawn and the single otolite of the auditory capsule, this species indicates the peculiarities 

 of the section of Eolis to which it belongs. 



Fig. 1, 4, 5. Eolis olivacea of the usual colour. 



2. The same, rich brown variety. 



3. The same, dark, full-coloured variety. 

 6, & 7. Papillae, more highly magnified. 



8. Spawn. 



(The figures in this Plate have inadvertently been reversed.) 



