SYMPAGELLA AXOMALA, 



103 



The peiitactinie IiupodennaUa are of a moderntely large size. 

 Parataiigentials as long as 600 z-^; the unpaired proximal ray 

 somewhat longer than the paratangentials of the same spicule ; 

 thickness of rays near the center, up to ?A !>■. All tlie rays, the 

 unpaired ray not excepted, are straight and gradually taper 

 towards the sharply pointed end, which is subterrainally nearly 

 smooth or sparingly supplied with obsolete microtubercles. 



Pentactinic liypogastralia are, as a general matter, not present 

 in this species. In this respect it is like S. nux (F. E. Sch., 

 '97, p. 529) but unlike S. Johnston i. It is possible that their 

 absence is in a measure compensated for by the occurrence, before 

 mentioned, of parenchymal tauactins and stauractins in touch 

 with the gastral layer. 



The dermalia (PI. VIII., figs. 4 and 5) are exclusively 

 hexactinic pinnies. The stoutly developed pinular ray is club-like 

 or spindle-like in shape. Starting fioni the base, it is smooth 

 for l-\ the entire ray-length ; then it commences to thicken as 

 the rhachis and to send out obliquely upwards and outwards a 

 number of elongate-conical scale-like spines. The conically pointed 

 apex of the rhachis projects more or less at the tip as the central 

 conus. The development of the entire ray is subject to a not 

 inconsiderable variation according to individuals, as may be seen 

 by comparing figs. 4 and ö which are taken from two different 

 specimens. In a certain specimen, the ray never exceeded 100 1^ 

 in length and 35/^ in greatest breadth, while in another it often 

 reached a length of 148/-« and a breadth of 40/^ with a greater 

 number of lateral spines. — The five remaining rays are all much 

 more slender and taper gradually towards the conically pointed 

 end. A number of rather sparsely set conical microtubercles 



