BIOLOGY. (II, A: B, i, a — d.) 
Echin. 39 
9. Nervous System and Sense-organs: — Vacant. 
10. Mesodermal tissues (exc. skeletal) : — Vacant. 
11. Axial organ : — Vacant. 
IS. Genital System : — Genital tubes in Stichopus, their meaning 
in Hoi. generally ; Mitsukuri (224) p. 8,— of Synapta , 2 caeca, 
bilaterally placed ; Polara (260). 
c. ECH I NO IDE A . 
1. General Accounts: — Anat. ; Kuekenthal (173) p. 132. — 
Practical dissection of Arbacia or Strongylocentrotus for students; 
Pratt (261) p. 139 : see also Thomson (304). — Detailed account 
of skeletal and internal anat. of Palaeopneustes , and structures 
at apical pole of Echinus ; Wagner (316). 
2. Symmetries : — Vacant. 
3. Homologies with other Classes :— Jaws homologous with 
adambulacrals of A si., and dental sacs with outer periliaemal 
ring ; MacBride (207) p. 314. 
j. Stereom : — Account of Hesse (159) Zool. Pec. 1900 ; Hamann 
(125) p. 1313. — Structure of plates of test in Echinocorys, esp. 
E. ciplyensis ; Lambert (176) p. 27, f. 21. 
5. Skeletal Anatomy :— Terminology ; Savin (283) pp. 69-75. 
— General description of test and appendages in Echinocory- 
tinae; Lambert (176) pp. 11-30. — Apical system of Cidaris 
elegans 14 mm. diam. descr. and figd. ; Seguin (292). — Plates 
in buccal membrane of Echinidae , Echinometridac &c. ; 
Mortensen (229) p. 95, and under spp. indexed in iv, c. 
Pedicellariae, — different kinds in Ech. collected by ‘ Siboga ’ ; 
de Meijere (53) i>. 15: this abstracted in Hamann (125) 
p. 1315. — History of opinion, description of different kinds esp. 
in Echinidae , Echinometridae , and Echinothuridae , serve as 
basis of classification (pp. 4-10), detailed descriptions under 
spp. indexed in iv, o; Globiferae of Hamann (pp. 117, 169); 
Mortensen (229). 
Sphaeridia, — in Offaster and Galeola (p. 22) but not in 
Echinocorys', Lambert (176) p. 30. — Origin from radioles in 
Echinus, and homologues in Ast . ; Mortensen (227) p. 78, fig. 
Radioles of Cidaridae (p. 13, pi. xi), of Echinothuridae (p. 44), 
of Echinidae , Echinometridae &c. (p. 94) ; Mortensen (229). 
Spicules, different kinds (p. 10), detailed descriptions under 
spp. indexed in iv, o ; Mortensen (229). 
6. Hydrocoel and associated cavities: — Podia of two forms 
in Micropyga ; de Meijere (53) p. 15. 
7, 8. Vacant. 
9. Nervous System: — New nervous organ in larval Echinus ; 
MacBride (208 & 207). 
10,11. Vacant. 
IS. Generative System : — Chemical constitution in relation to 
histology of ova in Stronqi/locentrotus and Sphaerechinus ; 
Bertolo (13). 
d. A S TEROIDEA . 
1. Gonoral Accounts :— Anat. ; Kuekenthal (173) p. 125. — 
Practical dissection of Asterias vulgaris for students ; Pratt 
( 261) p. 131 : see also Thomson (304). — Dissection of Ast. disc 
and part of ray; Jordan & Heath (160) p. 149, fig. 95. 
2-4. Vacant. 
5. Skeletal Anatomy :— Arm-structure of Ordovician spp.; 
Jaekel (154). — Numerous structural details esp. concerning 
spines, paxillae, papulae, pedicellariae, disc-plates in spp. of 
Mimaster , C heir aster, Porania, Lophaster (w. tubular paxilla- 
