io8 



Cat. S (PI. XIX) has a length of 377,3 cm., a length hitherto unknown for Siphonophores. 

 When we were unravelling the stem, it often happened that it snapped off, but we were 

 able to reconstruct the whole, as the appendages, especially the gonodendra show a very slow 

 but very gradual development. We were thus enabled to put together those parts in which 

 the stages of development revealed the succes.sive steps. Especially in Cat. 8 this succeeded 

 remarkably well. 



We should have liked to publish a sketch of the whole, but as the specimen is too large 

 too be sketched on one plate (PI. XIX) we left out parts which do not show anything particular 

 in their development, and could easily be left out, without disturbing the harmony of all the 

 gradual stages of development of the appendages. We call the different loops in which we 

 laid the stem as it is represented in our drawing on PI. XIX A., B., C, D., E., Y ., G. 



Between C. and D. 15,5 cm. of the stem and its appendages are left out, between D. 

 and E. 42,5 cm., between E. and F. 49,3 cm., between F. and G. 31,5 cm. Of course these 

 measures are not quite exact, as the stem is in some places spirally wound, or contracted 

 owing to the preservative fluid. To give a general idea of the structure of this large specimen, 

 we will not only describe the parts drawn on PI. XIX but also the intermediate parts. 

 A. The first part has a length of about 26 cm. The pneumatophore (length 2 cm., breadth 



Yj cm.) is elongate, cylindrical, seems abnormally small for such a long siphosome (compare 

 with P/crophysa (BatJiyphysa) Stnderi PI. XXII, fig. 153). The porus is clearly to be seen, 

 not so the hypocystic villi, as the outer wall is whitish opaque, and they do not shine through. 

 On the dorsal wall we very soon see the first indications of appendages, as small buds 

 which gradually change into small cylindrical tubes of some length. The breadth of the stem 

 is 2^., mm. These buds develop more and more till about 2 cm. below the pneumatophore, 

 the largest has attained a length of i cm., a breadth of 2^\,, mm. With Schneider 98 we 

 consider these appendages young, immature siphons; they are identical with Bedot's pneuma- 

 tozoids, but the complicated internal structure at their base is wanting entirely. They show 

 already the first indications of Fewkes' so-called ptera on each side. After these 2 cm. the 

 stem shows a first spiral winding to the left and the )-oung siphons which in the beginning- 

 were situated very closely together now show a small interval between them. They increase 

 more and more in size; as the ptera are somewhat contracted, the siphon has a curved 

 aspect, its apex being bent convexly. .Some siphons do not show this pecularity, they are 

 straight. One side of the pteron-band, is not broader than one third of the whole circum- 

 ference of the siphon. 



A median longitudinal section of the siphon (PI. XXIV, fig. 1 70) detached from the 

 stem about 14 cm. distally from the base of the pneumatophore taken near its apex, shows 

 that here there is already an aperture and that we are justified in considering these young 

 buds identical with future full-grown siphons. Near the distal part of A the length of such 

 a siphon is already 2 cm. The stem in part A gets narrower near the base, but preserves 

 throughout its whole length the same appearance. It is transparent, whitish, strongly muscular, 

 many times twisted and contorted. Near the proximal part of B we find that the stem gets 

 broader, more like a ribbon; furtheron it becomes similar again to the first part of the .specimen. 



