4° 



PENNATULIDA. 



These four specimens show the following proportions: 



Nr. 



Total length in mm. 



Length of the peduncle 



Greatest thickness of the peduncle 

 Length of the polyp-calyx 



136 



37 



15 



I 



The specimens Nr. 1 and 4 are unfortunately rather badly preserved; Nr. 3, which is figured on 

 PL III, fig. 33, twice the natural size, has been broken just above the peduncle (which has been added 

 after one of the other specimens); in the three specimens (2, 3, 4) the upper part of the rhachis is 

 bent with the concavity towards the ventral, polyp-bearing side; in the specimen figured in fig. 33, 

 moreover, a rather abrupt bending is found, ca. i5 mm from the point, possibly a healed up fracture. 

 The upper part of the peduncle is dilated in the form of an ellipse; the calcareous axis is also 

 enlarged here and reaches its greatest thickness; the calcareous axis is round, and ends both below and 

 above without being bent into a hook. There is no terminal polyp, but the rhachis ends as a naked 

 process containing the end of the calcareous axis. The polyps are placed along the ventral side of 

 the rhachis in two rows, each really belonging to one side; two polyps are often placed almost 

 opposite to each other, making, as it were, a pair; the}' then touch each other at the base, so that 

 no naked ventral streak is left between them; now and then, especially at the upper end of the 

 colony, groups of three polyps are found (comp. fig. 34); in this case one of these polyps is always 

 distinctly younger than the two others, and at its base is partly coalesced with the one belonging 

 to the same side as itself, and always placed obliquely immediately below; two such polyps form the 

 first beginning of a wing. In some part of the rhachis, especially in its lower half, large polyps 

 alternate tolerably regularly with smaller ones; several polyps (not only farthest down towards the 

 peduncle) have evidently appeared quite recently. The zooids are small and only found on the 

 ventral side, placed between the polyps, often but one or two above each polyp. 



The polyps are provided with a very marked, conical calyx, the ventral edge of which projects 

 into two strong points; sometimes these points are very long. They are close together on the side turned 

 away from the stem, but on the side towards the rhachis they are separated bv a broader and much 

 deeper indentation, from which projects the fore part of the polyp with the circle of tentacles. The 

 largest calyces measure 2.5 — 3 mm to the end of the points. The calyx is abundantly provided with 

 spicules, especially dense in the long points; the other part of the polyps shows spicules only along 

 the aboral side of the tentacle-stem. The longest spicules of the calyx I have measured, are 1.024""" 

 long and fully 0.048 — 0.064""" broad ; the average size of the long calyx-spicules is 0.8 — 0.96""" in length 

 and 0.040 — 0.048"™ in breadth; the smallest calyx-spicules are 0.08 — 0.128""" long and 0.007 — 0.016""" broad ; 

 the tentacle-spicules have been measured to a length of 0.122 — o.i44 mm , and a breadth of ca. 0.0014""". 



The whole stem is provided with lengthy parallel spicules, of a length of 0.096""", a few 

 rougher ones 0.144""" long and ca. 0.032""" broad. The lower end of the peduncle is sparingly provided, 

 and the spicules here become quite small, oval or round, 0.008 — 0.016""" long; here and there a few 

 longer ones, up to 0.064'""'. All the spicules — apart from the quite small ones — are of a marked 



