Fig. 22. — A quadrant of the umbrella corona with a sense club in the middle, twice the natural 

 size, subumbral view. Exactly in the middle of the figure, we see an interradial rhopalium (or), half 

 concealed by its ampulla (oa) into which a spheroidal air bubble has found its way. A sense lobe (Id), 

 the point of whose marginal selvedge is turned over inwards (above), is visible on either side of the 

 sense club (or). Next comes an adradial tentacle (ta), then a tentacle lobe (It), and finally a perradial 

 tentacle (tji). Only the basal parts of the tentacles are given. The coronal muscle (mc), whose upper 

 or proximal margin (mcj forms the lower or distal boundary line of the large coronal sinus (cs), is 

 drawn in the right half of the figure. The subumbral surface of the coronal muscle is laid in ten to 

 twelve strong circular folds (mc.,) winch decrease in height the lower they are and alternate with the 

 same number of circular furrows (mc 3 ). The lower or distal margin of the coronal muscle (mc^j is in- 

 serted with a projecting point in the middle of each marginal lobe (at its fused clasp Id), whilst it forms 

 a projecting roof, under which a small subumbral funnel cavity remains open (it) above the basal inser- 

 tion of each tentacle and each sense club. The broad distal margins of insertion of the longitudinal 

 deltoid muscles, the perradial (md') and the interradial (»"'"), are visible above the upper margin of 

 the coronal muscle (mc x ). Each of the four visible marginal lobes (/) is surrounded at the free distal 

 margin by a delicate folded membraneous selvedge ("patagium, lp"), and is halved in the middle by 

 a strong cartilage-like fused clasp (" cathamma lobare," Id). This arises by a fusion of the umbral and 

 subumbral wall of the lobe pouch, by means of which the latter is divided into two parallel canals (bl). 

 But as the thickened distal end of the fused clasp (Id) does not reach to the distal end of the lobe 

 pouch but stops above it, the two parallel canals of each lobe communicate below by a U-shaped 

 " horse shoe canal," whilst they open separately above into the coronal sinus (cs). In the left lobe of 

 the figure, a large air bubble expands the horse shoe canal enclosing the distal end of the fused clasp 

 (M") in its concavity. In the adjacent ocular lobe, the horse shoe canal is opened and its subumbral 

 wall retroverted on both sides ; we see the branched, blackish streaks of pigment (gd, glands ?) which 

 lie along the fused clasp (li) in the umbral wall (dn). In the figure to the left above, the coronal 

 muscle is removed for the most part to show the peculiar insertion of the tentacle (t/p), with its two 

 root muscles (mk), and also the peculiar septal fissure (be") by which the abaxial avelar pouch (be"") 

 communicates with the axial velar pouch (be'). The sequent (second) tentacle (left from the sense 

 club) is cut off short below its insertion (ct). The third tentacle (right from the sense club) is 

 cut open at the base of its length in order to show the remarkable double valved vent hole which 

 separates the tentacle cavity (ct), from the coronal pouch (be). The roundish cavity of the venthole 

 (ex) opens between the upper (yk') and the lower {yl~") vent valve. 



Fig. 23. — A band-shaped gastral filament, six times the natural size. 



Fig. 24. — Transverse section though a thick gastral filament, with strong gelatinous plate, 100 

 times the natural size. 



Fig. 25. — Transverse section through a thin gastral filament, with weak gelatinous plate, 100 times 

 the natural size. 



Fig. 26. — End of the narrow margin of a gastral filament. 600 times the natural size. 

 z Supporting gelatinous plate, ze Cells of the gelatinous plate (colloblasta). fd Bottle-shaped gland 

 cells, fe Narrow cylindrical endoderm cells between the glands. 



Fig. 27. — Small piece of a gastral filament, seen from the surface in order to show the distribution 

 of the gland cells (fd) between the narrow cylindrical cells of the endoderm (fc), 600 times the natural 

 size.' 



Fig. 28. — Gastral epithelial muscular cells (?) from a gastral filament, isolated by maceration, 600 

 times the natural size. 



