PENNATULIDA. 19 



Apart from the uppermost wing the other wings contain more than one polyp, as at all events 

 a rudiment of one or two polyps more is found in each wing to the ventral side of the oldest one. 

 In the uppermost pair of wings but one (II) the polyp of the left side (1) carries a small protuberance)*), 

 which I take to be the first trace of individual Nr. 2; the right wing has a distinct individual 2, but 

 still in the zooid-stage; in wing III, polyp 2 is large and well-developed on either side of the colony, 

 but nothing is seen of 3; in wing IV, polyp 2 is still larger, and 3 is present as a zooid; in wings 

 V— VII there are also 3 individuals, but 2 is smaller than in the preceding wings, and decreases in 

 development below, while 3 is still only a zooid in all of them; in wing VIII there are only two 

 polyps, of which Nr. 2 is only a zooid. The four rudimentary wings (IX— XII) consist, each of them 

 - more or less distinctly -- ot two individuals, both still zooids. 



Of zooids, there are 2 longitudinal rows dorsally, one on either side, separated by a bare 

 streak (i. e. devoid of individuals), about o.5 mm broad below, narrowing above (a similar naked streak 

 runs along the rhachis between the polyps of the ventral side); in each row an indication of a 

 grouping into 3 — 4 zooids for each wing may be traced. The series is already- indicated below at the 

 smallest rudiments of wings. - - Between the uppermost wing and the next the series is very open, 

 and onlv one zooid is found at each of the uppermost polyps (I). The zooids look like small scales 

 supported by spicules. At the upper end of the rhachis the rows are completed by a median, con- 

 siderablv larger, single top-zooid, Z. provided with two distinct calyx-points 1 ). Of lateral zooids, one 

 seems to be begun immediately above each wing, with the exception of the two uppermost pairs of 

 wings. These rudiments, however, are very small, and difficult to determine with certainty. 



The spiculation is copious and dense; the longest spicules are found on the polyps, the 

 next on the zooids and rhachis where they are mostly arranged longitudinally; there are also many 

 transverse, rather long and thin, spicules on the peduncle, intermingled lower down with longitudinal, 

 short, oval ones; towards the terminal bulb the spiculation diminishes to open, longitudinal rows of 

 short, oval spicules, and the bulb itself has no spicules, and is therefore transparent, so that the 

 interior longitudinal septum is seen (but no terminal pore; I think upon the whole that the existence 

 of such a pore in Pennatula normally is very doubtful 2 ). 



The spicules (espeeiallv with regard to the long ones) are of quite a different type from that 

 predominant in Penn. phosphorca. The fact is that all the spicules (excepting the oval ones in the 

 peduncle) are distinctly and sharply triangular, recalling mostly those of Penn. grandis. The longest 

 measured are 0.784""" long, 0.04""" broad; the short and thick ones are respectively o.i6o mm and 0.04— 

 0.112""", and 0.032"""; the small oval spicules of the peduncle are 0.064— o.o88 mm long, and o.oi6 mm broad. 



The calcareous axis terminates above, bent to the right, opposite to the third uppermost 

 wing, and below, also curved, just above the terminal bulb. 



The sexual organs are fully developed; they may be seen shining through the po- 

 lyps without any further preparation, but still more distinctly by clearing with oil of cloves; in 



■) In this specimen the top-zooid has by chance been wedged in between the two uppermost polyps, so that it is 

 only partly seen in the figure, but both from the dorsal and the ventral side. 

 2 ) Comp. Jungersen, 1SS8, p. 161. 



3* 



