250 TRANSACTIONS LIVERPOOL BIOLOGICAL SOCIETY. 



forming a reticulate skeleton echinated by spined styli. 

 Megascleres of the ectosome smooth diactinals. Micros- 

 cleres isochelae, with or without sigmata and toxa. 

 Myxilla granulata, B., XLV. 

 ,, irregularis, B., XLIV. 



jecusculum, B., LXXXIII. (Carter, 1, p. 237.) 

 ,, pansa, B., 4, I. 



peachi, B., 4, XIII. (Topsent, 18, p. 109.) 

 ,, pilata, B., 4, II. 

 ,, pulchella, B., 4, II. 



Genus Pocillon, Topsent {19, p. xxxiv). 

 Agreeing with Myxilla m structure, but having bipocilH 

 in addition. Differing from lophon only by the possession 

 of echinating spined styli. 



Focillon hyndmani, B., XL VI. (Hanitsch, 9, p. 217.) 

 ,, scandens, B., XLV. 

 ,, spiiiulentuvi, B., XXIV. 



Genus Lissomyxilla, n.g. 

 Skeleton fibres of the choanosome formed of smooth 

 monactinals, echinated by spined styli. Megascleres of 

 the ectosome smooth diactinals or monactinals. Micros- 

 cleres (isochelye, etc.,) may be present. 



Note. I have ventured to make this new genus for a 

 form which I could bring under no existing genus. 

 It differs from Myxilla only by the smooth styli of 

 the choanosome, and stands to Myxilla in the same 

 relationship as Lissodendoryx, Topsent, to Deiidoryx, 

 Gray. Topsent {18, p. 108) speaks of the possibility, 

 of a genus of the above character having to be created 

 sometime. I have left the definition of the new 

 genus wider than was really necessitated by the only 

 known species of it, so that allied forms may be more 

 easily included under it. The present species has 



