118 Proceedings of the Royal Irish Academy. 



rather different from the ease shown in her fig. 11. which was made under 

 difficulties, as the specimen was not weli preserved, and is, I think, exceptional. 

 When more typically shown it is not a strong sphincter, if we compare it, for 

 instance, with the powerful muscle of -£)■ 1 48. PI. VI, 



fig. 3), and it is more attached to the wall than Miss Eees' figure indicates — 

 not merely by a narrow pedicel, but by a broader area of attachment. 



Family PARACTIDAE ; E. Hertwig. 

 Actiniina with well- - and basilar muscles. Sphincter 



igloeaL Acontia absent. 



Sub-family ACTINOSTOLINAE 1 Carlgren. 



Paractddae in which, in the younger cycles of mesenteries, the individual 



icb pair an- unequally developed, exactly according to the 



following rule: — The largei mesentery of each pair (Le. the older) has its 



longitudinal retractor muscle turned towards the nearest mesentery-pair of 



the next oldest cycle. 



Actinostola Verrill. 



A tii stolinae with smooth or tuberculated bodywall, which may be very 

 thick. The oral disc may be more or less undulated in outline. Margin 

 tentaculate. Tentacles numerous, in more than two cycles, with or without 

 basal swellings of met 2 iboral side. longitudinal musculature 



of tentacles and radial musculature of oral disc entirely embedded in the 

 mesogloea. Numeroi . the primaries at least, and usually 



more, Bterile. Pennonj 



B. A. atrostoma n. sp. 



PI XT PL XV. fig.7; PL XVI. figs. 11, 12, 16-20; 



PI. XVII. figs. 1-4. 6-8, and 17. 



1. SB. 4^7 and 4*!>. 4 Large specimens. 



SR . - ■■•-. 3 L9 N. 51 36'; Long. W. 11 



Trawl. 540-660 fathoms. 

 8&4 Sept 4 L907. Lat. N. 51 35' ; Long. W. 11° 55'. 



Trawl. 720 fathoms. 



1 I should like to state here th.it in this paper I am only usim.' the families Paractidae 

 ib-familiea Acttnostolin&e and Pai nbactia 



and Actina | and geni i nl andei I 



have V- ig for some tie mewhat different grouping of all the 



genera at pi I in the families Paractiii i - .irtiidae. and hope to pub- 



lish it shortly. But as it is not convenient to enter here into the long discussions 

 involve.], I am retaining ■ nt cla.ssi6cation in the meantime. 



