ECHINODERMATA. 641 
PouRTALES (/. c. p. 355) recoi’ds the following Crinoidea from 
the same locality : — 
Antedon Jiagenii^ Pourt. ; A. ineridionalisy A. Ag. ; A. armata, Pourt. ; A, 
ctd>ensisf Pourt. ; A. 7'uhiginosa, Pourt. ; A. bf'evipuma, Pourt. ; Pentacrinus 
mulleri, CErst. j Phizocrinus lofotensis, Sara. 
PouRTALEs records (/. c. p. 359) the following Holothuroidea 
also from the same locality: — 
Cuvicria operculata, Pourt, ; Thyonidium conchilegum, Pourt. ; T. geinmatimi, 
Pourt. ; JEcJiinociicumis typica, Sara ; Cucumaria frondosa, Gunner ; Mol- 
padia horealisj Sara. 
Development, 
Here we may mention the important notes appended by Aw 
Agassiz to his Report on the deep-sea Echini c. p. 279), 
on the young stages of Echini. He was enabled to study the 
changes due to growth in no fewer than thirty-two species. 
The changes some species undergo arc so great that nothing 
would have been more natural than to place the two extremes 
of the series, not only in different species but often in dif- 
ferent genera. Detailed descriptions, accompanied with figures, 
are promised shortly. In the present notes brief allusions are 
made to the changes undergone during growth by Toxopneustes 
drohachiensiSy Ag.; Cidaris, Echinometra, Echinocidar is, Echinus, 
and allied genera ; by the Temnopleuridie ; by the Clypeastroids, 
as Echinarachnius, Mellita, Encope, Echinocyamus ; by the 
Spatangoids. It would be impossible, within the limits of this 
Record, even to indicate the remarkable peculiarities in these 
young forms described by A. Agassiz ; but their importance 
in relation to classification cannot be overlooked. Removing 
Echinoneus from the Galeritidje, A. Agassiz would associate the 
Galeritidie having teeth with the true Echinoids. 
Metschnikoff (/. c. p. 27) mentions the following as facts 
now pretty well established by his observations on the develop- 
ment of the Ophiuridee : — 
1. The ambulacral system and the side plates arise from one 
and the same origin. 
2. Both layers of the tegumentary system of the larvse un- 
dergo, at a certain point, a thickening, and immediately become 
differentiated into a shape according to that of the perfect 
animal. But as, after the formation of the star bodies, some of 
the provisional calcareous rods enclosing portions of the skin 
remain attached which later disappear, so it may be assumed 
that they are not directly transformed into the tegumentary por- 
tions of the Ophiurid, but are either thrown off by degrees or 
are absorbed by the star. 
3. The transformation of the bilateral larva into a radial form 
is accomplished by the retreat, both in the dorsal and ventral 
