318 THE VOYAGE OF H.M.S. CHALLENGER. 



case of the lowest whorls this may be due to the cmi having been soldered to the bottom 

 by calcareous expansions, I have never seen any ti'aces of such a condition. 



In the first place, there is a stem-fragment of Pentacrinus asterius, consisting of a few 

 iuternodal joints with a nodal joint beneath them which is somewhat worn and has its 

 central canal closed up by a low rounded tubercle ; so that it must have been detached 

 for some time from the infra-nodal joint which completed the syzygy. But all the cirri 

 borne by this modified nodal joint are perfect throughout their whole length, nearly 

 70 mm., and were most certainly not soldered to the bottom at the time the animal was 

 captured. 



Then again, in a fine Pentacnnus millleri from Martinique with a stem 120 mm. 

 long, which is closed below at the thirteenth node, all the cirri of this node are perfect 

 from the base to the terminal claw. They reach 50 mm. in length, and are spread out 

 in different directions, two being curved sharply upwards, while the others are more or 

 less horizontal. Their general appearance is very similar to that of the long cirri of 

 Antedon phalangium. But not one of them shows any trace of having been soldered to 

 the bottom. The cirri of the next four whorls above are all long enough to have touched 

 the bottom had the animal been attached like the individuals of Pentacrinus ivyville- 

 thomsoni dredged by the "Talisman." Eight of these twenty cii'ri, four in the first 

 whorl, two in the next, and two in the highest one, are now more or less broken ; but 

 this is clearly due to accident, and not to the fracture of an attachment. The same may 

 be said of a specimen of Pentacrinus millleri in the Natural History Museum, which has 

 a stem 135 mm. long, with several of the lower cirri remaining unbroken; while the 

 under surface of the twelfth nodal joint at which the stem ends is worn and somewhat 

 rounded, and bears two or three attached Foraminifera. The animal cannot, therefore, 

 have been attached by the base of the stem, though the cirri may have been soldered to 

 the bottom ; but their appearance is against this supposition. 



The same remarks apply to Pentacrinus alter nicirrus, in which the cirri reach 50 mm. 

 in length. Those of the four or five lowest whorls turn more or less directly downwards, 

 and all reach below the level of the terminal nodal joint, which may be anywhere between 

 47 and 155 mm. from the calyx. But none of these cirri in any of the twelve individuals 

 which I have examined show any signs of having been soldered to the bottom. Many of 

 them are now broken ; Ijut others are cpite perfect, though they must have been in 

 contact with the bottom, had the animals been permanently anchored like the " Talisman " 

 examples of Pentacrinus wyville-thomsoni. The single Pentacrinus dredged by the 

 Challenger on hard ground belonged to this species ; and as all the cirri of the lowest 

 whorls are more or less broken, it is quite possible that they may have been torn away 

 from a permanent attachment to the bottom. Another conclusive argument against the 

 general application of the " Talisman " observations is afforded by the condition of the 

 single specimen of Pentacrinus maclearanus which was dredged by the Challenger from a 



