FROM THE INDIAN AND PACIFIC OCEANS. 27 



and I now add five more, bringing the total number of Spongodes up to 

 87+4 + 7 + 5 = 103 and Spongodia to 8. Considering the slight variations on which 

 many new species are formed, these numbers are probably far too large; but so long as 

 the present method of classification of the genus is adopted, it is necessary to record 

 details of variation. 



The most interesting form in the present collection is undoubtedly S. biformata, in 

 which the flattened branches bear polyps of alternating sizes; a table of measurements 

 is given with the description of the species. It is most unfortunate that the cell-layers 

 are in such a poor state of preservation that it is impossible to make any histological 

 observations on it ; but the regular alternation of long stalked and short sessile polyps 

 is sufficiently pronounced to suggest that a thorough investigation might prove 

 interesting to anyone who is fortunate enough to obtain a similar specimen fresh or 

 well-preserved. It is probable that polyps of alternating size occur in all species that 

 have flattened foliate branches. Such appears to be the ease in S. rubescens, but the 

 lower branches are all so much broken that it would be rash to make a definite 

 statement. 



Lastly, I do not follow Kiikenthal in changing the name Spongodes to Dendro- 

 nephthya. The name Spongodes was invented by Lesson 73 years ago, and Kiikenthal can 

 find no better reason for changing it than its similarity to the allied genus Spongodia. 

 The similarity, if apt to be confusing, is not, in my opinion, sufficient to justify the 

 change, and throughout I have employed the original name. 



Spongodes thomsoni, sp. n. (PL 3. fig. 4 ; PL 4. figs. 17, 18, 19 ; PL 5. fig. 35.) 



Belonging to the Divaricate ceroicomis group of Kiikenthal. Two specimens. 



A. — Length 18 cm., greatest breadth 9 cm., sterile stalk 2 cm. Main stem gives off 

 branches up its entire length more or less at the sides in one plane. These break 

 up into a large number of twigs bearing bunches of 3-10 polyps. Polyps on stalks 

 1-2 mm. long, and borne at right angles to stalk. One spicule projects beyond each 

 polyp-head for 1 mm. Spicules of anthocodia in 8 double rows arranged en chevron, 

 one large spicule to each point, other smaller spicules irregularly disposed. Stem- 

 spicules various: curved spindles O'SxOT to TOxO'05 mm.; mostly irregularly tri- or 

 quadriradiate forms reaching 05x0-4 mm. from arm to arm; all covered with warty 

 projections. Branch-spicules : curved spindle type l'O X 0'05 mm. Spicules of partition- 

 walls very scarce and minute, 01 X 0-02 mm. Tentacles double row of small irregular 

 spicules about 005 X 0-01 mm. Spicules of supporting bundle 27 X 01 mm. 



Colour. Stem and main branches yellowish white; twigs becoming gradually orange; 

 polyps white. 



B. — Length 19 em., breadth 7'5 cm., sterile stalk two-fifths of whole length. Mode 

 of branching and spiculation of stem, branches, partition-walls, and anthocodiae like 

 that of specimen A. 



Colour much paler. Twigs never becoming more than a pale yellow ochre. Polyps 

 white. 



Hab. Bay of Bengal. 



4 s 



