Plate II. 



Scyplddmin lonf/hpino (Lt.). P. 22. 



Fig. 1. Tlie typo specimen (Sei. Coli. Mus. No. 222); with two small 

 young individuals attached to the prostalia of the large ,one. 

 Natural size. All the other figures in this plate, except fig. 15, 

 are taken from the largest individual. 

 Dermalia in lateral view. 300 x . 

 Part of a {)entactinic hyiiodernialia. ir)0 x . 

 Gastralia. 300 x. 

 Hexactinose oxyhexaster. From a deep part of the wall. 300 x . 



Fig. G. Hemihexactinose oxyhexaster. From a deej) part of the wall. 

 300 X . 



Fig. 7. Discohexaster. 300 x . 



Fig. S. Outer end of a discohexaster terminal. Ahout 1000 x . 



Fig. 1). Micr(uliscuhexaster. 300 x . 



Fig. 10. Section of wall ; part adjoining th(i outer siiriace. Above, dermal 

 layer ; with a pentactinic }irostal and two strong diactinic jirostals 

 cut off. About 25 X . 



Fig. 11. Section of wall; ])art adjoining the inner surlac(,'. P»e]ow, gastral 

 layer. About 25 x . 



Fig. 12. Trabeculiü and thesocytes ; from a borax-carmine preparation. 

 The nuclei appear as deeply stained dots. The thesocyto product 

 is represented by the large, more or less globular, strongly stained 

 bodies. Smaller, mcire weakly stained and granular s|)hert's re- 

 present probably a stage in the development of tlie thcsocyte 

 ])rodnct. 450 x . 



Fig. 13. Chamber-rim ; not well ]n-eserved. 'J'he larger deeply stained dots 

 in groups are ]irobably arcli;oocytes ; the weakly stained spheres 

 of granular a})|)earance are likely tliesocytes not yet fully grown. 

 Stained with borax-carmine. 450 x . 



Fig. 14. Chamber-wall. Tlie deeply stained dots are pr<^bal)ly partly 

 archîeocytes and partly trabecular nuclei. Choanocyt(^ nuclei are 

 scarcely indicated in the figure. Strongly magnified. 



Fig. 15, Peculiar bodies of uncertain nature, consisting of well-stained 

 threads arranged in diverging l)unches or in a radiid manner. 

 Seen in one of the two young individuals attached to the jirostal 

 needles, 300 x . 



