I04 



shall see in Pterophysa how small these measures are in comparison with those of Rhizophysa. 

 In Cat. 20 A. it is pear-shaped, it bends somewhat towards the stem, probably an abnormal 

 condition through preservation. Where it changes into the stem, there is no real distinction 

 between the two. Pigment is not very distinctly preserved, it has been lost probably through 

 preservation. Immediately behind the pneumatophore the siphons are to be seen, budding from 

 the stem, and very soon we also see tentacles with tentilla and young gonodendra. These first 

 show themselves as small cone-shaped e.xcrescences on the stem but these gradually grow and 

 between the nineteenth and twentieth siphons the gonostyle is fully developed and the nine male 

 and one female gonophores together with the gonopalpon on each side-branch of the gonostyle 

 are differentiated. These latter all increase gradually in size and the most posterior gonodendron 

 is one beautifully-.shaped bunch of these appendages. 



The first part of the stem (12 cm.) shows us also how the stem is broad, more or less 

 swollen and transparent. It shows in this proximal part nearl)- everywhere the same breadth. 

 This changes suddenly in the distal jxirt, where probably not only many gonostyles, but also 

 siphons and tentacles have become detached. We suppose that the first part is somewhat 

 contracted and that the more normal condition is that of the distal one. The proximal part has 

 about 27 siphons sitting closely one next to the other, the largest attaining a length of 2^/^ cm. 

 Every siphon shows a tentacle at its base, or the remains of one, when it has become detached. 

 The tentilla show the structure characteristic of Rhizophysa Eysenhardti (PI. XXIV, fig. 172). 



The stem of the distal part (38 cm.) is nearly thread-like, it possesses fourteen siphons, 

 situated at considerable distances one from the other. They are much smaller, but do not differ 

 in structure from those in the first part. The)' all possess a tentacle with tentilla, or remains 

 of a tentacle at the base. Gonodendra have probably all become detached, in some cases only 

 the basal part of the gonostyle is to be seen. 



Cat. 17 B. resembles in shape more or less Cat. 20 A. It al.so shows a proximal (20 cm.) 

 part in which the stem is broader and a distal (35 cm.) part where the stem is thread-like. 



We have given a sketch of Cat. /y A. (PI. XXI, fig. 150) to show what the aspect of a 

 Rhizophysa Eysenhardti is which measures 136 cm. and which but for the small cluster of young 

 siphons under the pneumatophore, has a stem of absolutely thread-like appearance; it carries 

 25 siphons at irregular intervals; in its distal part some have fallen oft". They are small, compact, 

 probably all contracted through preservation. Between the 15"^ and 16''' there is a protuberance 

 on the stem which means probabl)' that there too a sijihon has been detached. No well-developed 

 tentacles nor tentilla are preserved, but we still found distinctly the tentilla characteristic of 

 Rhizophysa Eysenhardti. The gonodendra are all situated in the internodes between two siphons. 

 Their development from simple bud to mature bunch (in this specimen the last two gonodendra 

 show a very long thin gonostyle) can be followed along the stem. 



P'inally Cat. 17 A. (length 140 cm.) shows the same shape of the pneumatojjhore, stem 

 and siphons in Cat. 14 A. The stem, if possible, is yet thinner and more thread-like. A great 

 many appendages have become detached, so that the distal part, about 45 cm. is devoid of 

 any appendages. 



