Stephknson — Certain Actiniaria collected off Ireland. 113 



In studying the anatomy of these specimens, however, I End that it 

 presents a close similarity to that of B. longicomis, and consequently the 

 question arises as to whether the two species are really distinct. Carlgren 

 (1893) has already suggested the possibility of their identity. And, more- 

 over, there are two specimens in the present collection which I cannot, in 

 their preserved- state, and from external characters, definitely refer to either 

 one species or the other. 



Nevertheless, I am inclined to think that, in spite of these facts, the two 

 species are distinct, for the following reasons: — When preserved, closely 

 related species of Actiniaria lose their external distinctive characters to a 

 large extent, when there would be no difficulty at all in distinguishing them 

 if they were alive — for instance, from examination of hundreds of specimens 

 in their natural haunts, of Sagartia mivea and S. venusta, I have not the least 

 doubt that they are distinct species ; but if they were preserved, it would be 

 difficult, if possible, to distinguish them. Mr. C. L. Walton, who has seen 

 B. tuediae and B. longicomis alive, assures me that in that condition they are 

 quite distinct. With regard to anatomy, one would not expect striking 

 differences in two species which had, possibly, not long diverged from a 

 common origin; and my specimens of B. tuediae show just enough difference 

 to support the idea that it is not identical with, though near, longicomis. 



I do not wish to speak positively on the subject until I have seen the two 

 species alive and healthy, but for the present I prefer to keep them separate. 

 I will therefore describe the external appearance of my specimens, and note 

 how they differ in structure from B. longicomis. They differ in one respect 

 from Gosse's description. He says there are only 3 cycles of tentacles ; but 

 that is not very important, and there are different ways of reckoning the 

 cycles. So, as he does not give the number in each cycle, we may pass this 

 over, although my specimens have more than 3 cycles. 



External Characters. — (i) The specimen figured in PI. XIV, fig. '2: — 



Greatest diameter of oral disc and tentacles, 9 cm. Length of one of the 

 longest tentacles, 3'9 cm. Height of column, 4 - 3 cm. Diameter of mouth, 

 3'8 cm.; of column at middle. 5'3 cm.; of pedal disc. :'.■:! cm. 



Pedal disc well developed, but of considerably less diameter than the oral 

 disc. Substance of pedal disc and column similar, rather soft; the regular 

 radial striatums of the pedal disc go straight on over its margin, and run ap 

 the column. Column widening from below upwards, fairly thin-walled, and 

 not stiff. It has longitudinal striations, and transverse wrinkles and fin rows. 

 due no doubt to contraction, so that its surface has a somewhat papillose 

 appearance in parts, though there are no real warts or suckers. The margin 

 forms a very slight rim. but it is of the tentaeulate type. The prominent 



K.I. A. r-BOC, VOL. XXXIV, SECT. u. [Q] 



