724 Scientific Proceedings, Royal Dublin Society. 
the ectoderm, these cells are not numerous. The ectoderm of the 
gullet contains the usual gland-cells. 
Mesoglea.—The mesoglea is everywhere rather thin. That of 
the column is dense, made up of fibres running both circularly 
and longitudinally ; it stains very deeply with carmine. There are 
no mesoglceal muscles except the sphincter. The mesogloea of the 
mesenteries also stains deeply. 
Endoderm.—The endoderm is of the usual type. Zooxanthelle 
are everywhere present.1 The endodermal circular muscles of the 
column and tentacles are well marked. The muscles of the 
mesenteries have the usual hexactinian arrangement. The re- 
tractors form a well-marked pennon on the primaries and secondaries. 
The parieto-basilar muscle is present on the mesenteries of the first 
and second cycles. Mesenterial filaments are borne by the primaries 
and secondaries; the glandular streaks are best developed; they 
contain many thick-walled stinging cells as well as gland-cells. 
The filaments were, on the whole, not numerous or well developed ; 
but both the specimens examined were distended with ova. No 
acontia are present. The ovaries are of the usual structure, and 
contain numbers of nearly mature ova. 
P. chromatoderus is the only representative of the genus 
Paranthus, which was established 
and placed with the Paractidze 
by Andres on external characters 
only (‘ Le Attinie,” 1884). The 
Paractidee have been variously 
defined by Hertwig. Report on 
_ the Actinaria (“ Challenger” Hx- 
pedition), 1882, p. 41; Andres, 
“Te Attinie,” 1884, p. 200 ; 
Danielssen, “ Actinida’’ (Norske 
Nordhavs. Expedit.), 1890, p. 8; 
Paranthus chromatoderus.—Vertical section Carlgren, ‘Studien uber Nor- 
ofepperpetofesluna-vallshowingmesoyias! Gischo Actinion,” 1, 1893, D. 64 
see p. 731.) M°Murrich, Report onthe Actinize 
(‘‘ Albatross’ Expedition), Proc. U. S. Nat. Mus. xvi., 1898, 
1T notice that Simon (Beitrag zur Anatomie u. Systematik der Hexactinien, 
Inaugural Dissertation der Universitat Miinchen, 1892, p. 45) says, in his definition of 
the Paractide, ‘‘ Zooxanthelle in this family have so far not been recognised.” 
