314 Scientific Proceedings, Royal Dublin Society. 



Secondly, as to the number of tentacles : — 



Grosse gives a definite number and arrangement. He says 

 (Actin. Brit. p. 195) they, are " set in four rows : 6, 6, 12, 24-48." 

 We were able to count the number of tentacles with complete 

 accuracy in only four of our specimens, and these four were found 

 to possess 60, 46, 44 and 32 tentacles respectively ; and though 

 we could not discover the precise number in the remaining seven 

 specimens, we can state positively that they did not each possess 

 the definite number given by Grosse : the number of tentacles as 

 well as of warts depends on the size of each specimen. It should 

 be observed that Grosse himself, in his first account of the species, 

 described the tentacles as "about 48 in number" {Ann. and Mag. 

 Nat. Hist, ser. 2, vol. xiv., p. 283 : Tenby, pp. 361-363). This 

 description was based on a dozen specimens obtained at Lidstep, 

 and it seems that Grosse was led to adopt the definite and precise 

 number given in the monograph from the examination of the four 

 other specimens that were found at Ilfracombe. The arrange- 

 ment of the tentacles we were unable to ascertain. In this matter 

 again there is a discrepancy between the two accounts published 

 by Grosse. The earlier one states that the tentacles are set in two 

 rows ; the later one says that they are set in four rows, but that 

 the first three rows are so nearly equidistant from the centre that 

 on a cursory inspection there appear but two rows altogether. 

 There is evidently some relation existing between the number of 

 tentacles and the number of rows of warts. In two specimens we 

 found the number of tentacles was double that of the rows of 

 warts ; these were the two specimens mentioned already as having 

 46 and 32 tentacles respectively, and in them we found 23 and 16 

 rows of warts respectively. These were the only two specimens in 

 which we were able accurately to ascertain the numbers both of 

 tentacles and rows of warts, but in the other specimens our obser- 

 vations, though not enabling us to give the same precise information, 

 lead us to form the conclusion that the number of tentacles is 

 double that of the rows of warts. The transverse sections, which 

 we will presently describe, confirm this opinion. The mouth is 

 usually so puckered or the oesophagus so unequally protruded that 

 it is very hard to ascertain either the number or the position of 

 the grooves. One of the largest specimens we examined — that pre- 

 viously mentioned as having sixty tentacles — had its mouth always 



