23 
lationship between these organs and the spines which does not exist 
at all. It is beyond doubt that the claviform pedicellariæ are 
modified pedicellariæ in which the head is rudimentary or has quite 
disappeared, while the stalk-glands have been strongly developed. 
Further it is certain that two kinds of pedicellariæ may develop 
into the claviform type, viz, the ophicephalous and globiferous. The 
former case obtains in the Diadematidæ, the latter in the Toxo- 
pneustidæ. Concerning their occurrence it is known that they are 
found in the Aspidodiadematidæ, and in several of the Diadematidæ 
and Toxopneustidæ, in addition to Podophora and Colobocentrotus, 
and it seems not unreasonable to suggest that they will prove to 
occur in all of the Diadematidæ and Toxopneustidæ , As regards 
their function it is well known that they are mucus-secreting organs. 
In the “Ingolf” Echinoidea I, p. 170, it was maintained that 
the name “claviform” pedicellariæ could rightly be used only for 
those derived from ophicephalous pedicellariæ (those of the Diade¬ 
matidæ), and not for those derived from globiferous pedicellariæ 
(those of the Toxopneustidæ). Though it is correct that these two 
forms are morphologically different I now think it unnecessary to 
employ two different names for tb em, as they represent only an ana- 
logous development of these two kinds of pedicellariæ and not a 
special type of pedicellariæ. 
Finally a few words must be said in regard to Professor Agas- 
s i z’s remarks on the supposed occurrence of these organs in Ha- 
palosoma pellucidum: “On PI. 12, figs. 8—10 of the “Ingolf” Ex. 
Echini, Dr. Mortensen gives sections of an organ which remind 
one of cystacanths, but he calls them globiferous pedicellariæ, though 
they seem to be without valves or other calcareous deposits. He 
gives no further explanation of their structure in describing the 
globiferous pedicellariæ of Haplos. 1 ) pellucidum (Colobocentrotus, 
p. 32). 
In the “Ingolf-Echinoidea” I, to which Professor Agassiz 
*) Typographical error for “Hapalos(oma)". 
