604 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
and Ophiuroids, confined to the oral surface ; they are called 
azygopodous. Put in the ordinary linear way the proposed arrange- 
ment stands thus : — 
Branch A. Incaliculata. 
Stage a. Anactinogonidiata. 
Class 1. Holothurioidea. 
Branch B. Caliculata. 
Stage a. Anactinogonidiata. 
Class 2. Some Cystidea (?) 
Stage /3. Actinogonidiata. 
1st Subbranch. Statozoa. 
Substage i. Apelmatozoic. 
Class 3. ? Some Cystidea. Class 4. ? Some Crinoidea. 
Class 5. ? Some Blastoidea. 
Substage ii. Pelmatozoie. 
Class 6. Crinoidea. Class 7. Cystidea. Class 8. Blas- 
toidea (s.s.). 
2nd Subbranch Eleutherozoa. 
Division 1. Zygopoda. 
Class 9. Echinoidea. 
Division ii. Azygopoda (s. Stelleridea sens, em.) 
Class 10. Asteroidea. 
Class 11. Ophiuroidea. 
Concise definitions of the divisions and classes, in which the new 
terms freely proposed by the author are made use of, complete the 
paper. 
Echinodermata from South-west Ireland.* — Mr. W. Percy Sladen 
gives an account of the Echinodermata collected in 1888 by a Deep-sea 
Dredging Committee of the Royal Irish Academy. The cruise was made 
off the south-west coast of Ireland, and the most interesting forms were 
obtained from 345 and 750 fathoms. At the latter station the Elasipod 
Lsetmogone violacea was obtained, as well as Phormosoma placenta and 
P. uranus , and a new species of Porocidaris, which is called P. gracilis. 
Of tbe Asteroidea Pentagonaster balteatus and P. concinnus, Pteraster 
personatus, Hymenaster giganteus were new. Mr. Sladen contests the 
view of Canon Norman, that Nymphaster protentus Sladen is a synonym 
of P. subspinosus. As only eight stations were dredged at and forty 
species were found, it is obvious that the collectors, of whom the Rev. 
W. S. Green was the head, hit on a rich locality. 
Development of Holothurians.f — Prof. H. Ludwig has made a study 
of the development of Cucumaria planci , specimens of which were kept 
for one hundred and sixteen days ; after the eighth or ninth day de- 
velopment proceeds very slowly. The larvae and young are quite opaque 
and so full of calcareous bodies that the ordinary methods of preparing 
sections were quite useless. Owing to the small size of the cellular 
elements and the close approximation of the foundations of the various 
organs it was necessary to have sections no more than 5-7 fx thick. 
* Proe. Roy. Irish Acad., i. (1891) pp. 687-704 (5 pis.).’ 
t 8B. K. Prcuss. Akad. d. Wise. Berlin, 1891, pp. 179-92. 
