The Actiniae of the Plate Collectiou. 269 



tlie bases of the inner tentacles, though two lay in close proximity 

 to tJie larg'e central months. The arrangement of the months in 

 this individual and their relations to the mesenteries are shown in 

 text fig-ure A (page 270). Each mouth opens into a separate, 

 stomatodaeum which is longitndinally ridged; the larger central 

 months may possess either one or two siphonoglyphs, but never 

 more than one was found in any of the smaller stomatodaea. 



The dimensions vary according to the amonnt of elongation the 

 body has undergone in dilferent individuals, although the height of 

 the column is fairly uniform, being about 0.7 cm. In the oval 

 specimens one diameter is in the neighbourhood of 1 cm, while the 

 other may be any where from 1.1 to 1.7 cm. In the largest specimens 

 from Tumbes the column in its narrower diameter measured about 

 1.3 cm, while its longer axis was 9.0 cm. 



In the preserved condition the specimens are colorless, except 

 for a slight yellowish finge on the ridges of the stomatodaeum in 

 some individuals. A label accorapanying the specimens from Puerto 

 Montt States the coloration in the living condition as foUows : 

 "Weiss. Fühler mit sehr hell braunem Anfluge. Mundscheibe zu- 

 weilen braun, Mundrand weiss." 



Structure. The column mesogloea is finely fibrillar in 

 structure and is about as thick as the ectoderm. This is very 

 richly provided with clavate gland-cells, whose Contents stain very 

 deeply with haematoxylin, but at frequent intervals areas occur in 

 which the gland-cells are rauch less numerous and the epithelium 

 resembles that usually seen in Verrucae, though lacking the pyriform 

 cells. These verrucal areas are not sharply marked off at their 

 edges from the more glandulär epithelium, nor do they show any 

 distinct depression of the centre, such as usually occurs in Verrucae. 



The circular muscles of the column are moderately developed 

 and there is a distinct mesogloeal sphincter. In the smaller 

 specimens this had a clavate form (Fig. 56) and occupied almost 

 the whole thickness of the mesogloea at its distal edge, tapering off 

 gradually below, though separated throughout its entire width from 

 the endoderm by a narrow band of mesogloea. In the larger 

 individuals, however, it had a more linear form (Fig. 57) and was 

 relatively much less developed. The longitudinal muscles of the 

 tentacles and the radial muscles of the disc were moderate and 

 entirely ectodermal in position. 



