38 E chin. 
XIV. ECHINODERMA. 
iii. Phylogenies of smaller groups : — Genealogical tree of Hoi. , 
descendants of Proholothurioidea split into two branches of which one 
gives rise to the following families, grouped as indicated by brackets, 
(Pelagothuriidae) ( Syncdlact -, Elpidi -, Deimat -, Psychropot- idae) 
( Holothuriidae ), the other branch to Synaptidae , Molpadiidae , (AAo- 
palodinidae , Gucumariidae ) ; Perrier (254) p. 298 . — Synapta pre- 
serves trace of primitive bilateral symmetry of Cystid ; Polara 
(260). 
Evolution of Echinocorys , history of mutation, and table of filiation 
of spp. ; Lambert (176) pp. 147-151. 
Origin of Ech. from Ast. ; MacBride (207) p. 316. — Origin of Oph. 
from Ast . ; Jaekel (154) p. 112 . — Astrophyton a primitive form of 
Oph. ; Russo (280 & 281). 
Relations of Cyst, to Hoi., Ast., Oph., Crin. and derivation of Ech. 
from Blast, (p. 200), XJintacr. from Melocrinoidea (p. 176), Marsupites 
from Cyathocrinoidea (p. 180) ; Steinmann (299). 
(B.) MORPHOLOGY. 
i. Anatomy : — 
a. ECHINODERMA. 
1. General accounts: — Echinoderm anatomy; Goette (105) 
pp. 307-328. 
2. Symmetries: — Vacant. 
3. Homologies of Glasses: — of sphasridia and ambulacrals in 
Ast. and Ech. ; Mortensen (227) p. 79. 
Spiracles of Blast., bursae of Oph., and secondary hydropores 
of larval Antedon homologised, and said to have similar 
physiological relations to the perioesophageal genital cord ; 
Russo (278). 
If. Skeletal tissue or Stereom: — Recent and fossil Ech. 
stereom proved calcite not aragonite by chemical tests ; 
M eigen (218) p. 92. 
5-12. Vacant. 
b. HOLOTHU RIOIDEA . 
1. .General Anatomy :— General accouut, with diagram; 
Kuekenthal (173) p. 138. — Notes on internal anat. of Meso- 
thuria, Pseudo stichopus, Bathyplotes, Pelopatides , Benthothuria, 
Gastrothuria , Stichopus, Trochostoma ; Perrier (254). 
In Actinopyga mauritiana “ white integument of ventral 
surface closely covered with small but conspicuous pores ” [of 
which the nature is not discussed] ; Pearson (250) p. 199. 
2. Symmetries : — V acant. 
3. Homologies: — Vacant. 
If. Stereom : — Growth of sclerites from triradiate spicules (p. 330) 
also details of sclerites in spp. of genera listed under ill, a, ii ; 
Perrier (254). 
5. Skeletal An atomy : — Spicules of Myriotrochus rinki ; Oster- 
GREN (244) p. 14. 
6. Hydrocoel &c. : — Vacant. 
7. Coelom and other body-cavities: — Anat. and histology of 
blood-vessels in Holothuria ; Enriques (73) p. 2. — Aboral 
lacuna and sinus homologous with those of other Hoi. are 
atrophied in Synapta, while dorsal or genital lacuna near 
gonads has two diverticula bilaterally symmetrical ; Polara 
(260). 
S. Digestive System: — Anat. and histology in Holothuria 
tubidosa ; Enriques (73) p. 2. 
