ECHINODERMATA. 
559 
The fifth part contains a chapter on the systematic position 
of the Holothurioids (pp. 178-199). 
Chapter V. is on the manners and customs of the sub- 
class (pp. 200-202), and Chapter VI. on their geographical 
distribution (pp. 203-229). 
Development. 
Kowalevsky (/. c.) gives a somewhat detailed account of the 
development of Psolinus hrevisy Pentacta doliolumy and Phyllo- 
porus urna. Casting a general glance at the development of 
the IIolothurijE, it is to be noticed that all investigations hitherto, 
save those of Koren and Danielssen {Holothuria tremula)y are 
somewhat superficial. The Auricular! ?e, which were taken by 
J oh. Muller and Krohn for Holothuria-larvse, have since turned 
out, from the later researches of Bauer, to be Synapta-larvse. 
The development of the above species goes to show that all the 
Holothuriae with a terminal mouth-opening undergo no very 
particular metamorphosis. On the other hand, researches made 
on some ova of those with a central mouth-opening, show that 
these have a very different development, and one far more after 
the type of that described by Job. Muller in his Archives for 1856. 
But whether even these, though they certainly are developed on 
a different plan from the others, undergo a true metamorphosis, 
must be determined by yet future research. 
Classification, 
We endeavour to give Pomel’s arrangement of the Echinoidea 
in a tabular form as follows : — 
Fam. I. Spatangidas, with six subfamilies : — 
1. Eupatagin< 2 , EupataguSy Breynia, Trachyspatagm. 
2. Brissiri(s. Leskiay Brissus, Brisscpsis. 
3. Micrasterincc. Micrasterias. 
4 . Toxast.erincp. 7'oxasterian. 
6. Ilolasterintc. Jlolaster, Metnporinm. 
6. Ananchytince. Offastcr, Stcnonia. 
Fam. II. LampAdiformida;, with four subfamilies : — « 
1. EchinoneincB. a. EchinoneuSj Pyrina. b. DymsteVy Ilyhochjpus. 
c. Caratomes, Asterostoma, Pygaulus. 
2. Cassidulin^c. Pygurus, Echinanthusy Faujasia. 
3. ClypeasterincB. Chjpeastery Scuiellay Lagamwi. 
4 . Echmoconinee. EchinocomtSy EcJiinoctfamvs, PygasieVy Echinoclypus. 
Fam. III. Globiformidje, with four subfamilies 
1. CidarincB. CidariSy Orilwcidaris. 
2. EchinincR. ^ropeltisy Sabnacis, Tripne/ustes, &c. kc. 
3. EiademincB. Heterocidaris, Hemicidarisy Eiademay Pcdma. 
4. SaJenina;. Salenia. 
( Vide Pomel’s ‘ Observations sur la classification des Echiiiides ’). 
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