Beaumont — Fauna and Flora of Valencia Barbour, Ireland. 809' 



moments, as may be readily seen on inspection of plate i., in 

 James Clark's monograph. The character of the gonads is 

 regarded by both Haeckel and James Clark as the most im- 

 portant point, and is stated to be sufficient to distinguish the 

 two species at a glance. In applying the above definitions to 

 my specimens, it will be convenient to consider first those 

 organs and the tentacles ; not losing sight of the fact that the 

 tentacles and the genital saccules increase in number dui'ing 

 growth, and that the above diagnoses apply to fuU-gTown 

 animals about 25 mm. in diameter. 



In large Plymouth specimens, 18 mm. across the bell, we find 

 about 120 tentacles on each arm, the gonads broadly triangular 

 and arranged in pairs, each consisting of upwards of 80 saccules 

 arranged in 6-7 rows, the size of the saccules increasing from 

 the interradial to the perradial border of each band. 



It must be admitted that these agree closely with IT. auricula., 

 and. certainly do not fall in with the definition of S. octoradiatus^ 

 A few somewhat smaller Plymouth specimens, having 60-100 

 tentacles on each arm and 50-60 saccules in each genital band 

 arranged in 4-5 rows, bridge over the gap between the first 

 named and the largest specimens from Yalencia, and those fi'om 

 elsewhere of about the same size, 7-8 mm. diameter. These 

 have on each arm 50-70 tentacles and about 33 saccules in 

 each gonad in 3-4 rows, the perradial saccules the largest. 



Individuals of 5-6 mm. have 40-60 tentacles on each arm, 

 and about 25 saccules in 3 rows in each genital band. And 

 so one passes on to the smallest that I have seen, about 3 mm. 

 in diameter ; having 9-12 tentacles to each arm, and about 10 

 saccules in a genital band, which consists of a single row of 

 saccules for about one-third of its length at each end and a 

 double one in the middle. Yet even in some of the very small 

 individuals the greater size of the saccules of the perradial 

 border is already evident. From these facts the conclusion 

 may fairly be drawn, that we are dealing with a series belonging^ 

 to one species ; and since those of largest size conform very 

 closely to S. auricula, I am compelled to believe that all are 

 H. auricula. 



Of course it may be pointed out that the Yalencia Haliclystus 

 is mature and breeding, and has not the full characters of an 

 adult H. auricula. But it may be reasonably advanced that 

 they have characters appropriate to H. auricula of their size ; 



