408 * PROF. J. A. THOMSON AND MR. AV. D. HENDERSON ON [Apr. 10, 



expansion ))econie.s thin-walled and is readily ruptured. The 

 embryos appear- as elongated lemon-shaped bodies, 1 mm. in 

 length by 0'75 in maxinuim diameter. There are numerous ova 

 on the mesenteric bands. It may be suggested that the expansions 

 figured by May in C. longissima and G. strumosa are also repi'o- 

 ductive swellings. 



Locality. Wasin Channel, 10 fathoms. 



Sympodium punctatum May. (Plate XXIX. fig. 9.) 



A specimen spi-eading over a monocotyledonous leaf agrees on 

 the whole with the description which May gives of S. punctatum. 

 There are two sets of spicules — the upper layer whitish, the lower 

 layer deep red. The spicules are about 0'2-0'3 nun. in length ; they 

 are fundamentally of the spindle-type, but bear irregular warty 

 processes, often with sharply truncate ends. The white s})icules lie 

 irregularly in an almost continuous superficial covering ; the 

 deeper red spicules ai-e partly intei-locked by their waity, often 

 branched projections. The colour scheme is slightly different 

 from that of May's specimen, since the red spicules are almost 

 entirely confineil to the basal membrane. 



LocaUt)j. Chiraka shore, low spring-tide. Previoirsly from 

 Tumbatu. 



Sympodium cceruleum Ehrenberg. 



To this species we refer sever-al rather poor' specimens " of a 

 sea-green colour," with polyps which can be completely retracted. 

 The basal membrane is a broad plate, 33 mm. in uraxirrrum length 

 and 16 mm. irr maxirrnrm width. It is thin at the edges, but 

 1 mm. in thickness near the middle. 



The polyps have short tentacles on which the finger-shaped 

 pinnules are ar-ranged irr one row on each side, about 15 irr each 

 row. 



There is no trace of the calcar-eous bodies which Klunzinger 

 figur-es ; tlrer-e ar-e aburrdarrt zoochlorellie. The ccenerrchyma of 

 the colorry is hyaline arrd non-gr'anrrlar. 



Locality. Previously frorrr Tumbatu, Red Sea. 



Sympodium fuscum, sp. n. (Plate XXX. fig. 5.) 



A spreading colony, forming large flexible sheets attached to 

 basal parts of Zostera. The livirrg specimens were reddish browrr 

 all over, except the terrtacles which were drab-brown ; the pre- 

 served specimens are creamy-white. 



The stolorr is a membrarrous plate from 2-3 mm. irr thickness, 

 rather thinner at the edges. The polyps are irniformly distri- 

 buted over the surface, and are capal)le of corrrplete retraction 

 into the stolorr, thirs givirrg it a porous appearance, somewhat 

 honeycomb-like. The pores have a diameter of 1 rrrm., arrd are 

 about 0*5 mm. apart. Spicules are rrirrrrerous irr the stolorr, arrd 

 fornr a superficial network, irr the meshes of which the polyps 



