244 THE VOYAGE OF H.M.S. CHALLENGER. 



circular, measuring 25 mm. across ; the upper surface is very slightly convex. It is of a 

 firm, dense consistency. 



Seven autozooids arise around the edge of the capitulum ; they are retractile within 

 verrucal openings, which measure 4 mm. across ; the verrucal edges are scarcely indented. 

 One extruded polyp, with retracted tentacles, measures 8 mm. in height. The pinnae 

 of the tentacles appear to be short, and much less developed than those of the previous 

 species. 



The siphonozooids are conspicuous, about three within the range of 1 mm.; they pro- 

 ject sufficiently over the surface of the ccenenchyma to give it quite a roughened appear- 

 ance ; they are of a slightly paler colour than the surrounding surface. They are found 

 equally over the convex lower and convex upper portions of the disc, and are ovigerous. 



The colour of the colony is a dull red. 



The spicules measure : — The long slender spiny spindles 0'5-0"02 ; 0"4-0'02 mm. The 

 four-rayed forms 0'24-0'06 ; 0"34-0"l mm. The shorter spiny spindles 0'3-0'04 ; 

 0'24-0"04 mm. Some long rod-like spicules, with enlarged roughened heads, occur, 

 which measure 0'2-004 mm., and the double crosses vary from 0'l-006 to 0"06-0"06 

 and 0-06-0-04 mm. 



This species, especially in the auto- and siphonozooids, also resembles AiUhomastus 

 purpureus (K. and D.), but the difference in the spicules is very great. 



Habitat. — Station 235, Japan; depth, 565 fathoms. 



Genus Sarcophytum, Lesson, emend. Marenzeller. 



Sarcophyton, Lesson, Belange's Voyage aux Indes orientales, and Zoologie du Voyage de la CoquUle, 



Zoophytes, p. 92, 183L 

 Sarcophytum, Marenzeller, Zoologische Jalirbucher, Bd. i. p. 351, 1886. 



The colony is mushroom-shaped, polyps dimorphic ; autozooids and spot-like siphono- 

 zooids, placed on the upper surface of the colony, which forms a convex expansion, and is 

 supported on a stalk-like sterile stem. The disc in process of growth often becomes 

 wrinkled at the edges ; the folds for the most part becoming once again plaited or 

 remaining unaltered. The upper surface of the disc is generally soft and elastic ; 

 owing to the numerous openings of the siphonozooids it has a shagreen-like appearance. 

 The autozooids are perfectly retractile, and are more numerous towards the margins of 

 the disc ; they have not well-developed siphonoglyphes. 



The siphonozooids, with four very short and four longer septa, have the siphonoglyphes 

 well developed ; they are sexless. 



A compac/; outer layer of small club-shaped spicules is present, except on the basal 

 portion of the stalk. The spicules of the ccenenchyma of the disc are slender rods or 

 spindles, with scattered spines or warts, seldom exceeding 0'02 mm. in breadth. The 



