^GIRUS PUNCTILUCENS. 



behind them. Smaller ones occupy each side of the ridge to the tail. Dorsal tentacles 

 stout, linear, smooth, slightly compressed at the sides, and terminating in a blunt double apex, 

 the posterior half rising a little above the other : they are yellowish, sprinkled with white, 

 and having two or three transverse brown bands. Sheaths moderately sized, divided into 

 five mammilliform lobes, the external ones very large, the internal smaller. Branchial 

 plumes three, imperfectly tripinnate, of an obscure pellucid white, with a pale brown line 

 running along the principal stem and branches ; the whole minutely streaked with opake 

 white. The two lateral plumes have each a large posterior branch. Head indistinct, covered 

 by a small veil, the margins of which are scalloped into about eight or ten equal tubercles : 

 mouth tubular, situated in a depression between the veil and foot ; the lips fleshy, and outside 

 of them two indistinct oral tentacles. Foot whitish, with the sides nearly parallel, squared in 

 front, and slightly produced laterally into obtuse points. 



The spicula of the skin are very numerous, and crowded together without much apparent 

 order ; they are of different sizes, smooth, swelling a little and slightly bent in the centre, and 

 tapering to a point at each end. 



The Boris Maura of Professor E. Forbes, which we consider to be a variety of this 

 species, has the colour of the body darker, and the tubercles pinkish. We found a variety 

 somewhat similar in Lamlash Bay, Isle of Arran. 



This interesting and curious animal has at first sight rather an unattractive appearance, 

 and it is not until we examine it more carefully that its beauty becomes apparent. The 

 brilliant spots with which it is covered, give it the appearance of being studded with small 

 gems, each set in a dark frame. They vary from azure blue to emerald green, reflecting 

 either colour occasionally according to the light they are viewed in. 



JEgirus punctilucens has now been met with in several localities on our southern and 

 western coasts, and, though by no means common, appears to be pretty extensively diffused. 

 M. D'Orbigny first described it from a specimen found near Brest, and it has also been found 

 on the Swedish coast, where it appears to be more common than with us, as Professor 

 Loven remarks that it is sometimes gregarious. It is a sluggish animal, though the indi- 

 viduals we have met with are certainly much less so than the one observed by M. D'Orbigny, 

 which took five hours to traverse a vase little more than a decimeter in diameter. According 

 to the observations of that naturalist, it feeds upon small species of Ulvse. 



The spawn of E. punctilucens consists of a narrow gelatinous riband, cemented by its 

 edge to stones, and forming a spiral coil of two volutions. The ova are small, and placed in 

 close transverse lines of about ten each. 



Figs. 1, 2, 3. JEgirus punctilucens, different views. 



4. A tentacle more highly magnified, and exhibiting three of the brilliant spots 



at its base. 



5. A branchial plume. 



6. A portion of the skin with spicula. 



7. Detached spicula, more highly magnified. 



8. Spawn. 



9. A portion of the same showing the ova= 



