104 Scientific Proceedings, Royal Dublin Society. 



this band there is a Y-shaped brownish-red mark, the apex of 

 which points towards the mouth ; while on either side of the mouth 

 are two slightly- curved short linear marks running towards the 

 mouth. There are no markings on the disk which correspond with 

 the secondary tentacles. 



Dish (5 — translucent pale brownish-red, with no coloured mark- 

 ings corresponding to the mesenteries ; the bright-red oesophagus 

 shining distinctly through in the centre ; the mouth encircled 

 with an opaque white band, which was shaded off gradually into 

 the brownish-red which forms the general colour of the disk. Each 

 tentacle is marked at the foot with a crescent of opaque white : 

 these crescents, though they come very close to each, do not coalesce, 

 but are separated by a thin streak of the brownish-red which is 

 prolonged between them. Each crescent is shaded off into the 

 general colour of the disk on the side towards the mouth, while 

 the side next the tentacle is sharply and definitely drawn. 



Mouth a — with brownish-red lips ; on the inner edge of the 

 lips are six pairs of small white spots, which correspond with the 

 six lateral primary tentacles. 



Mouth /3 — with bright-red lips, quite plain, without marks or 

 spots. 



Dimensions. — 



Length — contracted, 35-40 mm. 



„ expanded, 65-70 „ 



Expanse of disk and tentacles, 8 mm. 

 Diameter of scapus, greatest, 5 „ 

 „ . „ least, 2 „ 



Locality. — Malahide, county Dublin, south bank of the estuary, 

 opposite the Hotel ; in mud, among stones, at extreme low water. 



I cannot conclude this description without stating that I am 

 well aware of the difficulty raised by the account given of the 

 arrangement of the tentacles in example j3. However, I can only 

 say that, after repeated observations made during the three months 

 the animal was alive — observations always made, I may add, almost 

 in the hopes of ascertaining the contrary to be the fact — I am 

 quite certain that ten, and not eight, was the number of the ten- 

 tacles in the inner row. In connexion with this point it is worthy 

 of note, that Quatrefages, in his description of the disk of the very 



