CAULOPtlACÜS LOTIFOLlÜM. ' 91 



The liypodermal, anastomosing Innidles of fibers, which may 

 be considered as a part of the parenchymal skeleton, seem to 

 consist of the diactinic elements only. 



The hypodermal peniacii/is in the sponge-body measure com- 

 monly between 300/^ and 600/'- in length of paratangential rays. 

 The proximally directed, unpaired ray is usually longer than, 

 but never so nuicli as twice, the length of the paratangential s in 

 the same spicule. Thickness of rays near the center 23-30 /A 

 The rays gradually attenuate towards the more or less conically 

 pointed end. Their surface is smooth except for a very short 

 space at the ends, which are rough. This holds true of all 

 the rays, not excepting the proximal ray, which in all other 

 known species of the genus seems to be echinated throughout 

 almost its entire length. The paratangentials form the dehcate, 

 more or less regularly quadrate-meshed, hypodermal latticework 

 before mentioned (fig. 19). — In the stalk, especially in its 

 lower part, the hypodermal pentactins (of which two are shown 

 in fig. 20) are nmcli smaller than in the body. Length of 

 paratangentials 100 ,« on an average ; the proximal ray 3-4 times 

 as long, sometimes bearing on the surface a small number of 

 minute prickle-like points. The pentactins are here irregularly 

 scattered. 



As hypogastralia there occur pentactins similar in all respects 

 to the hypodermalia of the body (fig. 21) ; only they are distri- 

 buted without order as to the mutual relation of the cruciate 

 paratangentials, so that these do not exhibit a checker-like 

 arrangement. They may associate with some parenchymal diactins 

 in forming the thin hypogastral strands. 



