HYDROZOA. 
Ccel. 21 
Plumularia turgida , p. 779, pi. xx, figs. 12 & 13, Lyttleton, N. Z., P. 
caliculata, p. 780, pi. xx, figs. 9 & 10, Bondi Bay, Port Jackson, P. alata, 
p. 782, pi. xix, figs. 6-10, hab. ?, P. aurita , p. 784, pi. xix, figs. 15-19, 
n. spp. ; id. 
Aglaophehidjg. 
Aglaophcnia sinuosa , p. 790, pi. xxi, figs. 1 & 2, Port Denison, A. macro- 
carpa , p. 791, pi. xxi, figs. 3 & 4, Port Jackson, A. phyllocarpa, p. 793, 
pi. xxi, figs. 9 & 10, Port Denison, A. (?) whiteleggei , p. 794, pi. xxi, fig. 8, 
hab. ? ; Bale. 
HYDROCORALLIA. 
Stromatoporidas. 
Ardnorluza, n. g. ; Wentzel, (2) p. 17. 
Circopora, n. g. ; id. t. c. p. 20. 
Disjectopom, n. g. ; id. t. c. p. 15. 
Irregulatoporci , n. g. ; id. ibid. 
Incertas sedis. 
Milcheldeania gregaria , n. sp., Carboniferous, Scotland ; Nicholson, 
(2) p. 17, figs. 1 & 2.* 
Solenopora ? filiformis, n. sp., Ardovician, Scotland ; id. t.c. p. 21, fig. 4. 
simoNornoRA. 
The * Challenger ’ Report is a complete monograph of this group. In 
the introduction the general morphology and special anatomy of the 
group are discussed ; a new view of their organisation, entitled the 
“ Medusome theory,” is propounded, in virtue of which the various parts 
of a colony may be “ either medusiform persons, or special organs of the 
same,” and this“ whether they bud out from a common basis on the stem, 
or arise in different positions, iu consequence of kinogenetic migration or 
dislocation.” The Siphonophorci are divided into two subclasses : the 
Disconanthcc , which are regarded as having been developed from Craspe- 
dotce; and the Siphonanthce, of which the Anthomedusce are considered to be 
the ancestors. There is an extensive bibliography, table of terminology, 
and a systematic list of the whole class ; Haeckel. 
Haeckel’s medusome theory criticised ; Ciiun (2). 
DISCONECTiE. 
DiscaliDjE, n. fam. 
Discalia , n. g., for D. medusina , n. sp., S. Pacific ; Haeckel, (1) pp. 45 
& 46, pi. xlix, figs. 1-6. 
Disconalia , n. g., for D. gastroblastci , n. sp., S. Pacific ; id. t. c. p. 48, 
pi. xlix, figs. 7-12, pi. 1, figs. 1-10. 
