Echinological Notes. 
By 
Dr. Tlu Mortensen . 
I. 
On the “Cystacanths”. 
In his magnificent work “The genns Colobocentrotus" (Mem. 
Mus. Comp. Zool., XXXVI, 1908, p. 30) Professor Agassiz has 
given the name “Cystacanths” to some “problematical organs” 
observed by Mr. W ester gr en in Podophora. Prof. Agassiz has 
further found these organs in Colobocentrotus and in Chætodiadema 
pallidum and he thinks that they also occur in Hapalosoma 
f i% Haplos.") pellucidum, judging from figs. 8—10, PI. XII of my 
“Ingolf” Echinoidea I. He adds that “it will be interesting to 
see if cystacanths are found in other echini and to obtain, if pos- 
sible, some clue to the function of these problematical organs which 
suggest affinities both to the poison giands of globiferous pedicel- 
lariæ and to the sac-carrying spines of Echinothuriæ” .... “They 
mav be modified sacbearing spines, such as are found among the 
Echinothuriæ or modified pedicellariæ in which the giands have 
developed into the giands of the cystacanths at the expense of the 
valves.” 
In “Zoolog. Anzeiger” 10. Aug. 1909 (Bd. XXXIV, No. 20—21, 
p. 623) Professor Agassiz publishes a short note: “Globiferen” 
and “Cystacanths”, in which he says that Professor Hamann has 
called his attention to the description of the “Globiferæ” of Sphære- 
chinus and Centrostephanus in the “Beitrage zur Histologie der 
Echinodermen” III. 1884; he agrees that “these organs are, as he 
2 * 
