514 EDITH M. PRATT. 



III. GENUS LOBOPHYTUM. 



Lobophytum (amended genus)' (PL XXVIII. fig. 7, PI. XXIX. figs. 12—14). 



As in Sarcophytum and Sclerophytum a colony consists of two parts: — the capitulum 

 and the stalk. The capitulum is the superior portion of the colony, and bears the antho- 

 codiae ; on its • surface are the apertures of the zooids. The capitulum is supported by the 

 stalk, by means of which the colony is attached to the substratum. The stalk has no zooid 

 apertures of any description on its surface, but is penetrated to the base of the colony by 

 the cavities of the primary autozooids. 



As in Sarcophytum, all the species are dimorphic, autozooids and siphonozooids being 

 both well marked. Young colonies are often mushroom-shaped (fig. 12), the capitulum repre- 

 senting the pileus of the mushroom. As the colony grows older irregular excrescences appear 

 on apparently any portion of the surface of the capitulum. These often attain a con- 

 siderable size, so that the original resemblance to a mushroom is entirely lost, and the 

 capitulum has an irregularly-lobed appearance (fig. 7). Calcareous spicules, imbedded in the 

 mesogloeal and often ectodermal tissues, are to be found throughout the colony. They are 

 usually very small, short and stout, or long and slender, and generally studded with large 

 warts, arranged in zones". Throughout the genus they are apparently similar to those 

 figured by Marenzeller (1886) in his original description. When clubs are present they are 

 few in number, and are not crowfled near the surface as in the new genus Sclerophytum, 

 in Acrophyttim and in Alcyonium. 



The autozooids are very well-marked, and are similar in form and general structure 

 to those of Sarcophytum, but much larger than Sclerophytum (figs. 2, 13, 22). The eight 

 tentacles are slightly longer and more slender than in any species of Sarcophytum which 

 I have examined. They are of the simple pinnate type with a single row of pinnules 

 down each side, the pinnules apparently less numerous in the younger than in the older 

 autozooids. 



The stomodaeum is very well-marked, but the siphonoglyph is not easy to distinguish 

 in the preserved state except in stained sections. All the mesenteries have mesenterial 

 filaments. The two dorsal filaments are similar in form to those of Alcyonium, and to those 

 of the siphonozooids, in that they are ciliated and grooved. The ventral and lateral mesen- 

 terial filaments are usually rounded in cross section, but here and there may be seen a 

 filament which is slightly grooved down the middle. The ova are similar in size and shape 

 to those of other Alcyonaria. I have been unable to find male cells in any of the specimens. 



The siphonozooids are very similar in form and function to those of Sarcophytum. 

 They have no tentacles, and only the two dorsal mesenteries bear mesenterial filaments. 

 These zooids have no special digestive cells, and do not bear reproductive organs. They 

 appear to be respiratory and excretory in function. 



The canal system is well developed and is similar in general structure to that of 

 Sarcophytum. It differs from Sclerophytum in the absence of a special superficial canal 

 system, which is so well marked in that genus. As in Sarcophytum transverse ciliated 



' A detailed account of the general and minute anatomy this genus, for similar spicules are present in Sarcophi/tun 

 of this genus will be published later. latum. 



■ The zoned character of the spicules is not confined to 



