GENERA^ SPECIESj &C. Spong. 10 
Spongilla jordancnsis, Vejdovsky, found at Rakonitz in Bohemia ; 
Kusta, Yerh. z.-b. Wien,xxix. p. 40. 
Hexactinellida. 
Schmidt, (9) p. 33, supports Carter’s views that siliceous bars, where 
found extending in this Order between the primitive skeleton spicules, 
are formed by silicification of extensions of protoplasm ; polyhedric 
skeleton -meshes may occur as constant modifications of the hexahedral 
type ; the scopiforrn, or broom-like spicules are modified sex-radiate 
forms, connected with the “ fir-trees.” 
Farrea, (9) p. 43. Schmidt does not consider the presence or 
absence of scopiforrn spicules a specific character ; many varieties occur 
in the Mexican and Caribbean Seas, but Farrea facunda, Schmidt, is the 
only good species existing there ; it includes F. fistulata and lonvis^ Bower- 
bank. Further remarks are made on Bowerbank’s species of Farrea. 
Eurete farreopsis, Carter, (9) p. 44, = Aulodictyon intermedium = 
Farrea. 
Aphrocallistes, (9) p. 48. Structure and growth discussed ; A. hocagii., 
1. c. pi. vii. fig. 5, 1G4-400 fath., Caribbean Sea, is perhaps identical with 
A. heatrix. 
Myliusia zitteli, Marshall, (9) p. $1. pi. iii. figs. 11 & 12, pi. iv. fig. 5, 
pi. vi. fig. 4, Caribbean Sea, 100-150 fath. and perhaps deeper. M. cal- 
locyathes., Cray, 1. c. p. 54, pl.viii. figs. 1-3, Caribbean Sea, 116-292 fath., 
= Dactylocalyx. 
Dactylocalyx pumiceus, (9) p. 53, pi. vi. fig. 5, subglobosus^ 1. c. pi. iv. 
fig. 8, Caribbean Sea. 
Dactylocalyx crispus^ Schmidt, (9) p. 47, is a mere growth-form, not a 
distinct species. 
Hyalonema, Pheronema a7ince, and Liobolidium, from various localities 
in the Caribbean Sea, (9) pp. 64 & 65. 
Sponge-balls formed of masses of Euplectella spicules supposed to have 
been ejected by a Cetacean animal ; T. Higgin, P. Liverp. Soc. xxxiii. 
p. Ivii. 
Euplectella aspergillum, (10) p. 663, pi. xvii. From carefully preserved 
specimens from H.M.S. ‘ Challenger ’ it was discovered that the soft 
parts are scanty in amount ; the wall of the sponge is traversed by per- 
manent openings, besides those in the plate at the top constituting the 
true vents ; the excretory tubes have smaller or larger openings within 
special areas on the inner surface ; the outer surface is covered by a skin 
which is pierced by dermal pores leading into a very irregular system 
of lacunar and canal-like subdermal spaces opening into cylindrical 
ciliated chambers about yVinni. by mm. in size; these have an outer 
closed rounded end and a wide circular opening, and are grouped around 
short digitate excretory co3ca which open either directly or by the inter- 
vention of large canals into the internal cavity of the sponge. Three 
tissue layers are distinguishable : the ectoderm, probably cellular, clothes 
the whole exterior and interior wall and the inhalent canals ; the endo- 
derm lines the ciliated chambers and the exhalent canals ; the inter- 
mediate tissue, which is reticulate, and contains the generative products, 
