246 



ALCYOXARIA OF THE MERGTJT ARCHIPELAGO. 



are generally stouter, shorter, and curved, and the verrucae 

 prominent, even in the closed condition. By its long, straight, 

 and slender distal internodes and the distribution of its colours, 

 it has more the appearance of Melitodes virgata, Verrill, or of 

 purple varieties of M. ochracea ; but a specimen of the latter in 

 the Museum differs in its very wide posterior bare area in hoth 

 ultimate and middle branches and its very squarely-cut nodes 

 (perhaps the colour and resemblance is largely due to fading, &c, 

 of both specimens). The ground-colour of M. virgata is (as im- 

 plied by Gray's synonymic appellation, atrorubens) a very dark 

 red. 



An undescribed species in the British Museum has rather 

 stouter terminal twigs and more or less prominent verruca;, is 

 non-reticulate and non-flabellate, and is further at once dis- 

 tinguished from M. planiloca by the evenly-rounded foliar lobes 

 of the " Blatikeule " spicule, and by the apparent absence of the 

 graceful fusiform spicule, and its replacement (?) by an irregular 

 nodular form. Perhaps, however, this is the most closely allied 

 known species. As positive characters of the new species may 

 be indicated the " high-shouldered " form of the foliate spicule, 

 the very slender cortical fusiform spicule, the very thin, smooth 

 cortex, and very small unprojecting verrucas. The spiculation 

 strikes me as being more varied than that of any Melithaeid known 

 to me, but this may be due to defective observation as regards the 

 remaining species. 



DESCRIPTION OF THE PLATES. 

 Plate XVII. 



Fig. 1. Psci'mmogor^ia? plexauroidcs, n.sp. Portion of colony (dry). Nat. size. 



2. The same. Tip of pinna. X 2 diam. 



3. The same. Spicule No. 2 of description. X250 diam. 



4. The same. Spicule No. 3 of description. X 250 diam. 



5 & G. The same. Spicule No. 4 of description, varieties. x250 diam. 



7. Ijobuplii/l it m madrcporoidc.s, n. sp. Portion of colony, showing stem &c. 



(.spirit). Nat. size. 



8. The same. Small portion from surface of pileus to show an autozooid 



and siphonozooids. x0 diam. 



9. The Bame. Deep spicule of stem, No. 1 of description. x2. r )0 diam. 

 10 & 11. The same,. Spicules of zooid-bearing portion. X250 diam. 



12. The same. Superficial spicule of zopid-bearing portion. X 250 diam. 

 18. Spongodea nigrotinpta, n. ip. Portion of head (spirit). Nat. size. 

 L4. The fame. A. lobule. X6 diam. 



15. The same. Projecting spicule. X 55 diam. 



16. The same. Spicule of general cortex. X 55 diam. 



