212 PERCY SLADEN TRUST EXPEDITION 



Ocean, To these specimens the specific name irregularis was assigned. Schulze's 

 diagnosis of the genus [1887, p. 380] is as follows: — "A thin-walled cup, much folded, 

 extended into lateral diverticula, and also continued into short laterally projecting tubes. 

 The cup is fixed by a firm irregular base. The connected framework of beams consists 

 of much curved hexacts, partly united by synapticula, partly soldered together. The 

 parenchyma contains loose discohexasters with short or with medium-sized principal rays, 

 bearing S-shaped terminals disposed in perianth-like fashion. Under the skin there are 

 large hexasters in which each of the short principal rays bears six long diverging 

 terminals, which gradually increase in thickness towards the round outer end, and are 

 beset all round with backward bent pointed hooks. The dermalia and gastralia are 

 rough medium-sized oxypentacts." 



Schulze placed his new genus in the family Rossellidge of the then still accepted 

 sub-order Lyssacina. I am not aware that the genus has again been met with excepting 

 by the " Sealark " expedition in the Indian Ocean ; but in his report on the Hexactinellida 

 of the Valdivia (p. 180) Schulze [1904] accepts a new arrangement proposed by Ijima 

 [1903], in accordance with which it is placed in the latter's new family Dactylocalycidee, 

 all the other genera of which are more or less typical dictyonine forms. 



1. Aulocalyx serialis n. sp. 



(Plate 40, figs. 1—10 a.) 



The largest and most perfect specimen (R.N. v. 1) has the form of a narrow, 

 obconical goblet, terminating above in a slightly contracted mouth without any sieve- 

 plate (cf tig. 1). The wall of the goblet is longitudinally folded, and the prominent 

 ridges on the outer surface appear to be made up each of a single row of short tubes 

 fused together. The principal rows of tubes extend longitudinally from the constricted 

 base of the sponge to the margin of the mouth ; as they extend upwards the intervals 

 between adjacent rows become wider and new rows appear between them. The tubes 

 have conspicuous external openings and lead right through the wall of the goblet into the 

 central cavity. Their internal openings lie in the bottom of longitudinal depressions of 

 the inner surface. Altogether there are some eight or nine rows of these tubular openings 

 in the wall of the sponge. In this specimen, unfortunately, the base of attachment has 

 been broken off; but two other specimens (R.N. v. 2 and R.N. Ixxxi.), which are in other 

 respects much less perfect, show how the body of the sponge gradually contracts below 

 and then expands into a small flattened disc of attachment (cf. fig. 1). The central 

 cavity of the sponge is continued downwards practically as far as the basal disc, and 

 there is no distinct stalk. The sponge is very fragile, the greater part of the body soft 

 and compressible, almost woolly, but gradually becoming much more rigid below, owing 

 to the stronger development of the dictyonal framework. All the soft tissues seem to 

 have disappeared, and the best specimen (R.N. v. 1) contains a considerable quantity of 

 fine white sand, consisting largely of foraminiferan and radiolarian skeletons. The 

 height of the largest specimen, without the basal disc, is about 70 mm., and the greatest 

 width, close to the top of the goblet, 29 mm. 



