8P0NGIIDA. 40] 



This species has a great resemblance to the West-Indian Tuba 

 sororia of Duchassaing de Fonbressin and Michelotti, but differs 

 from the West-Indian species included by Schmidt in bis Siphono- 

 chalina papyracea, of which T. sororia is one, in haying the spicules 

 •0063 millim. and upwards thick, instead of only '002 to '0042, as 

 stated by Schmidt for those species. 



SIPHONOCHALINA, Schmidt. 



Although apparently published (Spong. Kiist. Alg. p. 7) as dis- 

 tinct from Tuba of Duch. de Fonbr. and Michelotti, it seems to bo 

 coextensivo with that (older) genus. I have, however, provisionally 

 retained the name for convenience, for a tew forms with narrow, 

 tbick-walled tubes, liko those of tho type species S. coriacea (I. c). 



30. Siphonochalina tubulosa, var. 



Spongia tubulosa, Esper, Pfl-anzentk. Fortsetz. i. p. 100, pi. liv. 



Siphonochalina tubulosa, Elders, Die Espersch. Spong. p. 19. 



? Spongia bullata var. (3, Lamarck, Ann. Mus. Hist. Nat. xx. p. 437. 



Small colonies, some agreeing well with Esper's figure, some with 

 the tubes scarcely rising above the general surface. The skeleton- 

 spicules are rather longer and more slender than is indicated by 

 Ehlers's measurements, viz. -17 by -009 millim. (Ehlers gives "11 to 

 •13 by '012 millim.) ; the smaller ones mentioned by him are 

 obviously young. 



Several specimens, dry and in spirit. 



Hub. Thursday Island, Channel Ilock, Torres Straits, depth ? ; 

 Port Molle, Queensland, " beach." 



Distribution. Cape of Good Hope (Esper). 



31. Tubulodigitus communis. 

 Carter, Ann. # Mag. N. H. (5) ix. p. 307. 



The present specimens, preserved in spirit, agree sufficiently with 

 Mr. Carter's description as regards external characters. The colour 

 (in spirit) is chiefly a dark earthy brown, which may very probably 

 have been altered from the purple described by Mr. Carter. The 

 fibre is strongly horny, slender, and very flexible, -035 to -042 

 millim. in diameter in the case of the primaries, -028 to '035 in 

 the secondaries; spicules 1- to 3- (rarely 4-) serial in the primaries, 

 1- or 2-serial in the secondaries. In Mr. Carter's specimens the 

 spicules appear to be relatively somewhat more abundant. Colour 

 pale amber-yellow. Although I have not observed in these speci- 

 mens a constant difference in size between the axial and peripheral 

 spicules of the fibre, such as that which Mr. Carter notices (I.e.), there 

 is, nevertheless, a very marked dimorphism in the spicules. Between 

 those of the commoner, slender acerate form, gradually sharp-pointed, 

 size '1 by *005 millim., are intercalated in various places stouter 

 ones of similar shape, but in size 44 by "0063 millim., and thoy 

 sometimes occur by the side of the slenderer form. From the 



2d 



