458 Records of the Indian Museum. [Vo.. XI, 
Grade TETRAXONELLIDA. 
Family PACHASTRELLIDAE. 
Stoeba plicata (Schmidt). 
1868. Corticium plicatum, Schmidt, Die Spong. d. Kuste v. Algier, 
p- 2, pl. iii, fig. 11. . 
1880. Samus simplex, Carter, Ann. Mag. Nat. Hist. (5) V1, p. 60, pl. v, 
fig. 20. 
1888. Stoeba simplex, Sollas, ‘ Challenger’ Rep. Zool., Tetractinellida 
(vol. XXV), p..102. 
1888. Calcabrina plicata, id., tbid., p. 281. 
1889 (1887). Samus simplex, Carter in Anderson’s Faun. Mergut I, 
Pp: 75: 7 
1894. Dewottus plicata, v. Lendenfeld, Denk. Ak. Wien. LXI, p. 105; 
pl. ii, fig. 10, pl. mi, fig. 43. 
1895. Dercitus plicatus, Topsent, Arch. Zool. expérim. (3) III, p. 531, 
pl. xxii, figs. 6-10. 
1903. Dercitus simplex, Thiele, Abh. Senckenb. Natur. Geselisch. XXV, 
p..20, pl. it, Aig. 4. 
1903. Dercitus simplex & D. plicatus, v. Lendenfeld, Das Tierreich, 
Tetraxonia, pp. 81, 82. 
1905. Stoeba simplex & S. plicata, Dendy in Herdman’s Ceylon Pearl 
Fisheries, 111, pp. 71, 230. 
Carter mentions spicules of his Samus simplex as being among 
those he extracted from a specimen of dead coral in the late Dr. 
Anderson’s Mergui collection. From the same specimenI have 
been able to extract numerous pieces of this sponge in sufficiently 
good condition to study its general structure and spiculation ; 
the latter is evidently more varied than either Carter himself or 
Sollas realized and is apt to be not fully understood because certain 
spicules are practically confined to certain parts of the sponge. 
I am of the opinion that Topsent’s suggestion (1895, p. 536) as to 
the specific identity of the species with Schmidt’s Corticium 
plicatum is fully justified by the specimens I have examined. 
The sponge, as it exists in dead coral, forms small oval or glo- 
bular masses which entirely fill corresponding cavities. From 
‘these are given out slender, cylindrical or flattened branches, some 
of which join them to other similar masses, while others termi- 
nate in flattened and often ramifying lamellae, ‘The latter make 
their way among interstices of the calcareous material. The 
larger masses contain a dense crowd of well-formed triaenes ar- 
ranged with their sharply pointed shafts pointing outwards, but 
in the connecting branches the macroscleres are more scanty and 
more delicate in form, while they are practically absent in the dis- 
tal parts of the lamellae. In the proximal parts thereof they 
have precisely the form of the small slender spicules figured by 
Topsent (1895, pl. xxii, 0’, d’), whereas in the larger masses they 
agree equally well with the figures 0 and d on the same plate. The 
proportions of all these types of spicules also agree with Topsent’s 
description. Spicules of the ‘‘calthrops” type are extremely 
scarce in my specimens, Indeed, I was for some time of the 
opinion that they were altogether absent. After a prolonged search 
through spicule-preparations, however, I at last succeeded in 
