PLATE 42. 



Hyalonema (Hyalonema) agassizi Lendenfeld. 



Figs. 1-13, 25-28, 35, 36, 38-41, 49, 51, 52 — form A, Station 4656. 

 Figs. 14, 15, 29, 37, 47, 48, 50, 53, 54 — form B, Station 4651. 

 Fig.s. 16-23, 43, 44, 55, 56, 58 — form C, Station 4740. 



Figs. 24, 30-34, 42, 45, 46, 57, 59 — form D, Station 3684 (A. A. 17). 



1-8. — Side-views of gastral pinules from the surface of the gastral cone of form A; magnified 300; phot. 

 Zeiss, apochr. 4, compens. oc. 6: 



1, normal hexactine pinule with long proximal ray; 



2, normal hexactine pinule with short proximal ray; 



3-7, normal pentactine pinules; * 

 8, abnormal pentactine pinule. 

 9. — Minute pentactine from the surface of the gastral cone of form A; magnified 300; phot. Zeiss, 



apochr. 4, compens. oc. 6. 

 10-12. — Apical view of the lateral rays of gastral pinules from the surface of the gastral cone of form A; 



magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6. 

 13. — A diactine gastral pinule from the surface of the gastral cone of form A; magnified 300; phot. 



Zeiss, apochr. 4, compens. oc. 6. 

 14-19. — Side-views of gastral pinules; magnified 300; phot. Zeiss, apochr. 4, compens. oc. 6: 

 14, 15, from the surface of the gastral cone of form B; 

 16, 17, from the surface of the gastral cone of form C; 



18, 19, from the surface of one of the radial walls separating the canalicular diverticula of the gastral 

 cavity of form C. 



20-23. — Side-views of dermal pinules from the outer surface of form C; magnified 300; phot. Zeiss, 



apochr. 4, compens. oc. 6. 

 24. — Side-view of a gastral pinule from the surface of the gastral cone of form D; magnified 300; phot. 



Zeiss, apochr. 4, compens. oc. 6. 

 25-34. — Side-views of dermal pinules from the outer surface; magnified 300; phot. Zeiss, apochr. 4, 

 compens. oc. 6: 

 25-28, of form A; 

 29, of form B; 

 30-34, of form D. 



35, 36. — Apical views of the lateral raj's of two dermal pinules from the outer surface of form A; magni- 

 fied 300; phot. Zeiss, apochr. 4, compens. oc. 6. 

 37. — Surface-view of the dermal membrane on the basal part of form B; magnified 50; phot. Zeiss, 

 achr. aa, compens. oc. 6: 



a, hypodermal pentactines; b, dermal pinules. 

 38-41. — Modified, slender-rayed, long-spined pinules of the basal part of form A; magnified 300; phot. 

 Zeiss, apochr. 4, compens. oc. 6: 

 38, 39, hexactine foi'ms; 

 40, 41, pentactine forms. 



42. — Group of spicrdes from a spicule-preparation of the basal part of form D; magnified 300; phot. 

 Zeiss, apochr. 4, compens. oc. 6: 



a, microhexactincs; b, dermal pinules. 

 43-45. — Modified, slender-rayed, long-spined pinules from the basal part of the sponge; magnified 300; 

 phot. Zeiss, apochr. 4, compens. oc. 6: 

 43, 44 of form C; 

 45, of form D. 



46. — Spined, slender-rayed hexactine acanthophore of form D; magnified 300; phot. Zeiss, apochr. 4, 



compens. oc. 6. 



47, 48. — Modified, .slender-rayed, long-spined pinules from the basal part of form B; magnified 300; 



phot. Zeiss, apochr. 4, compens. oc. 6. 



49. — A slender-rayed, long-spined tetractine acanthophore of form A; magnified 300; phot. Zeiss, 



apochr. 4, compens. oc. 6. 



50. — Minute pentactine of the basal part of form B; magnified 300; phot. Zeiss, apochr. 4, compens. 



oc. 6. 



51-59. — Slender-rayed, long-spined tetractine and pentactine acanthophores; magnified 300; phot. 

 Zeiss, apochr. 4, compens. oc. 6: 

 51, 52, tetractine ones of foi'm A; 

 53, 54, tetractine ones of form B; 

 55, 56, tetractine ones of form C; 



57, a pentactine one of form D; 



58, a pentactine one of form C; 



59, a tetractine one of form D. 



