1(J8 ACTINLE OF ALBATKOSS EXPLORATIONS M^MURRICH. 



compared them. They measure about 8"" in lieinht, witli a diameter of 

 5.5'^'"'. JNlost of the si)ecimens (PI. XXV, Fig. 17) are only jiartially eon- 

 tracted, allowiui;- the tentacles to partially protrude, but in some they 

 are entirely concealed from view. 



The base is tiat, marl<e<l with line radiating lines, and has the lim- 

 bus folded back over its edges in all the specimens. The column is 

 nearly cylindrical, and slightly smaller above than beloAv. Its wall has 

 a tirm, parchment-like consistency, and is variously corrugated, in part 

 owing to contraction. In the more fully expanded specimens the sur- 

 face has somewhat the ai)pearance which beaten silver or other soft 

 njctal presents, while in others the corrugations may be sufficiently 

 l)ronounced as almost to justify the designation of irregular tubercles. 

 There are, however, no indications of verruca'. Below the margin the 

 mesoghea is rougher than elsewhere, and is raised into irregular ridges. 

 The column wall has a snowy white appearance, the ectoderm in all 

 the sijecimens having almost disappeared; the fragments of it which 

 remain in some specimens seem to indicate that it Avas of a pale, brown- 

 ish -pur[)le color. The sphincter (PI. xxv, Fig. 51) is well developed 

 and extends a considerable distance down the column wall. In its 

 upper part it does not occupy the entire width of the column wall, but 

 lies throughout its course nearer the endodermal surface thau the ecto- 

 dermal, its cavities passing, in fact, directly into the ordinary circular 

 nuisculature of the endoderm. It does not expand suddenly above, 

 but its upper part, though larger than the middle region, tapers oft' 

 very gradually as it is traccnl downwards. In its upper part the closely 

 packed muscle cavities show a tendency to be arranged in longitudinal 

 bands (PI. xxv. Fig. 52) separated from one another by streaks of 

 nearly homogeneous mesoghea, and recalling the arrangement which 

 Hertwig ('82) has described for his Dysactis erassicornis. 



There is no well-dedned margin, the tentacles being inseited upon it. 

 They are rather numerous, situated close to the nuirgin, and are short 

 and stout, with well-marked pores at their extremities. They have a 

 more or less decided pink or salmon <'(>lor, and are rather indistinctly 

 longitudinally fluted. Their longitudinal nuiseulature is imbedded in 

 the rather thick mesoghea (PI. xxv. Fig. 48), as is also the radial mus- 

 culature of the disc. This portion of the body is smooth and concave 

 and has the same pinkish color which occurs in the tentacles. The 

 mouth is wide, and \\\e, stomatod.eum is about half the length of the 

 body. It is longitudinally ridged, and has two well-marked, deep 

 si])honoglyphes with smooth walls, which are continued down below 

 the lower edge of the stomatodieum, almost to the base. 



Twenty-four pairs of mesenteries reach the stomatodieum, but twelve 

 of them are muted to the stomatodaMim to a less extent than the other 

 twelve. In addition to these there is another cycle of twenty-four im- 

 l)erfect i)airs, which may be counted as the fourth cycle, while the fifth 

 cycle of forty eight pairs, also imperfect, presents the anomalous cou- 



