NEW OENERA AND SPECIES. Sp 07 ig. 9 
some of the spicules at any rate are found at an early stage outside the pro- 
plasm of the cells, some within cells. 
Sycandra raphanus. (7) pi. xxi. figs. 7 & 8 ; embryonic stages de- 
scribed. Also stated by Vosmaer, Tijdsch. Nederl. Dierk. Yer. iv, p, cix., 
to derive its ova from the mesoderm. All stages are seen, from the 
spindle-shaped cell to the ripe ovum ; the segmentation proceeds unsym- 
metrically after the third division ; the embryo is at first cylindrical, 
open at both ends ; it becomes closed, and after the free stage settles 
down and is invaginated. 
Sycandra sp. P, (7) pi. xxi. figs. 19 & 20, Embryonic stages figured. 
Leucandra aspera, (7) p, 370, pi. xxi. figs. 17 & 18, xxii. fig. 6. Embry- 
onic stages closely resemble those of Sycandra. 
Wagnerella borealis^ Mereschk., is, according to P. Mayer, Zool. Anz. ii. 
p. 367, no Sponge at ail, but a Heliozoan found commonly at Naples. An 
appearance of budding is imparted by the ascent of the nucleus into the 
head, and its division while there into eight pieces. 
New Genera and Species. 
Carnosa. 
Chondrilla succiformis, Carter, (1) p. 299, pi. xxvi. figs. 9, 11, & 12, 
Mauritius. 
Ceratina and Psammonemata. 
Oligoceras^ F. E. Schulze, (10) p. 34. Distinguished from other 
Ceratosa by the slight development of the horny skeleton, which has 
only occasional horizontal fibres ; primary fibres branching, full of foreign 
bodies ; in soft parts agrees with Cacospongia. 0. collectrix^ id. 1. c. p. 34, 
pis. ii. fig. G, iii. figs. .6-7, Lesina, Adriatic. 
Hipposp>ongia, Schulze, fO) p. 614. Based on Euspongia equina, 
Schmidt. Characterized chiefly by a system of circular meandrine anas- 
tomosing canals, 5-10 mm. broad, occupying most of the substance, and 
by lacking the straight principal fibres at right angles to the surface. 
Chalinula fertilis, Keller, (5) p. 318, pis. xviii. xix. & xx. figs. 24 & 25, 
27-29, Gulf of Naples. Monozoic or polyzoic ; the ectoderm, a layer 
of flat cells, meets the endoderm at the osculum. Has great contractile 
powers ; besides the oscula, it is perforated by permanent openings, or 
dermal ostia, leading into canals, and by transitory openings, or dermal 
pores, finer and sieve-like, leading into subdermal spaces ; the gastral 
cavity and afferent canals, except perhaps the subdermal spaces, are 
clothed by endoderm. The collar-cells agree with those of Reniera. 
Three sets of skeleton- fibres, viz., radial, longitudinal, and circular. Sexes 
distinct ; males thin and slender, females twice or three times their size 
at the sexual period, when the latter assume a rosy colour. The sperma- 
tozoa occur in capsules lined with epithelium; ovarian capsule surrounded 
by many granular, probably nutritive, cells ; segmentation total, but un- 
equal. No cleavage cavity ; endodorm-cells imperfectly invaginated, pri- 
mitive mouth filled by a plug of yelk. Mesoderm formed by the outer 
of the two cells into which each primitive endoderm cell divides. Spicula 
first appear in the periphery near the yelk-plug. The females perish 
