248 THE SPONGES OF THE WEST-CENTRAL PACIFIC 



The ectosome color in life is a dark dull red, and the endosome a lighter, 

 brighter red, like fresh beef liver. The consistency is also exceedingly like 

 that of fresh mammalian liver. 



The surface is very smooth, but in life there are pores 30 p. to 50 ll in 

 diameter and about 60 li apart. The oscules are very few in number but as 

 much as 4 mm in diameter when fully opened. These are contractile, and in 

 many specimens are closed upon collection. 



The ectosome is a thin, very fleshy dermis, and the endosome is also 

 densely fleshy, like mammalian meat or liver tissue. The flagellate chambers 

 are about 30 li in diameter. 



The skeleton comprises megascleres which are much like many that are 

 found in the genus Plakortis, species simplex, which spicules are regarded as 

 being reduced triaxons. These are ostensibly oxeas, but are bent about three 

 times near the middle of the spicule. In none of the specimens of Plakortis lita 

 which were studied could even a single triaxon be found. This is quite re- 

 markable. It is even more noteworthy that in almost every specimen, there 

 are such unusual microscleres that it is almost suitable to erect a new genus 

 for the species lita. In some of the specimens the microscleres are as much as 

 7 il long, but in the type specimen they are only 5 ll long. These need to be 

 studied with oil immersion and, even so, each appears to be merely a many 

 times bent rod, less than 0.5 ii in diameter. There are commonly from 12 to 

 15 sharp bends. The possibility exists that this is a spiral spicule, but this was 

 not the impression obtained under the microscope. 



This species is unique for its microscleres and also for the complete lack 

 of triaxon spicules. The extremely liver-like consistency is also worthy of 

 some comment. 



The species name here selected is chosen merely for euphony and is not 

 particularly descriptive. 



GENUS PLACINOLOPHA Topsent 

 Placinolopha mirabilis, new 



Text Figure No. 172 



This species is here represented by the following : 

 U.S.N.M. No. 22939, My No. M. 309, here designated as type, collected 

 June 20, 1949, by diver in the channel near Bikajela Islet at Ailing-lap- 

 lap Atoll. The depth was 10 meters, and the substrate was dead coral. 



This specimen is between massive and amorphous, about 4 cm thick and 

 4 cm in diameter. 



In life the ectosome color was dull carmine red and the endosome ochre 

 yellow. The consistency was between spongy and cartilaginous. 



The surface is microtuberculate and is lipostomous, even the oscules 

 being closed. 



