110 Proceedings of the Roi/al Irish Academy. 



Teutaeles fairly short, stiff', moderately slender; one medium-sized specimen 

 had 38 of them, of rather irregular sizes, the inner on the whole larger than 

 the others. Another specimen had 41. 1 have not yet worked out exact 

 details as to relationship between tentacles and mesenteries, but judgingfrom 

 the development of mesenteries in the specimen sectionized, the number of 

 tentacles would reach about 68 in the fully grown animal. The throat is 

 rather wide, and the oral disc consequently narrow. 



There is m> trace of a sphincter. The longitudinal musculature of the 

 tentacles and radial musculature of the disc are entirely ectodermal (PI. XX. 

 figs. 2 and 8), and not very strongly developed. The mesenterial filaments 

 have ciliated lobes. The upper part, at any rate, of the bodywaU ectoderm 

 presents an interesting and characteristic feature. It possesses localized 

 batteries of thick-walled nemal these batteries vary in size and density, 



but often form an almost solid mass of sting-cells. Between the various 



batb . typically has tl \ i almost absent. 



(PI. XV] The body wall ectoderm also contains a moderate though 



not large, Dumb tnd the bases of the supporting cells are 



distinctly thickened. 



Thei : ies, arranged on the usual hcxactiniau 



plan, i.e., there are 2 Lirectivee, and 4 ordinary lateral pairs. These 



macromet - all l>ear very Btrong circumscribed retractor muscles and 



mesenterial filaments; and in the larger of two sectionized specimens 10 of 

 the 12 bore well-developed testes; these could not be seen on the other 2, 

 which were damaged, but they may have been present. One specimen showed 

 a curious ami presumably accidental I ol the macromesenteries 



had the n the part of the mesentery 



just above the level of the enterostome; but it was well developed both 

 e and Mow that level. Beside the circumscribed retractor, the macro- 

 ■ which a - all perfect) have rather feeble parietal 



muscles, which di _ tdually into a fringe of processes between them and 



the retractor < PL XIX. fig. 1 ). 



In each of the four i found a pair of micromesenteries 



with no developed filament, retractor, or gonad). These 

 run down the whole length of the body, from oral disc -to base, but are quite 

 nan the way, i>earing simply parietal muscles, whose proce- 



cannot be said to be better di on one face than on the other, though 



there seem- to l>e a tendency tter development on the 



sentery than on the other. But at the very 



become jiiBt broad enough to 



I tect ), and have there a distinct longi- 



