340 HYALONEMA (OONEMA) CRASSIPINULUM. 



129. The individual anchor-teeth are usually not curved quite uniformly, and 

 pointed at the end. Their end-parts are parallel or slightly di\ergent. 



The broad-anchored small macramphidiscs (Plate 93, figs. 3-8; Plate 94, 

 figs. 1-3) are very much rarer than in the allied species. They are 110-200^1 

 long, and have a smooth cylindrical shaft 8-17 n thick. Their anchors are 

 57-100 fi long, usually 1-G /j more than half the whole spicule, and 58-172 n 

 broad. The proportion of their length to their breadth is 100 to 101-179, on an 

 average 100 : 144.6. It is to be noted that the smaller of these spicules have 

 relatively narrower anchors, the larger relatively broader anchors. Thus the 

 proportion of anchor-length to anchor-breadth is in those under 130 /i in length 

 100 to 101-148; in those over 180 m in length 100 to 150-179. The most fre- 

 quent number of anchor-teeth is eight. The teeth of the two anchors of the 

 same spicule are usually situated alternately (Plate 93, figs. 5, 7) ; sometimes, 

 however, all the teeth, or at least some of them, lie opposite, and appear to l)e 

 in contact with each other (Plate 93, fig. 3). The outer contour of the teeth 

 usually at first slightly ascends. It is uniformly curved, concave to the shaft 

 to within a short distance from the tip of the tooth, and abruptly bent inward at 

 the end. The keel of the tooth extends as far as the curvature of the outer 

 contour continues uniform. At the point of maximum breadth, which lies about 

 two thirds of their length from their base, the teeth measure 22-31 ^^ in trans- 

 verse diameter. Distally the teeth are slightly attenuated. The end is rounded. 



The narrow-anchored small macramphidiscs (Plate 93, figs. 1, 2; Plate 94, 

 fig. 4) are very rare. I observed only fi^•e of them, and it is possible that they are 

 foreign. These spicules are 112-137 ^ long. The shaft is 5-7 ju thick, slightly 

 centrotyle, and roughened with indications of spines. The central tyle is 1-3 jj. 

 more in transverse diameter than the adjacent part of the shaft. The terminal 

 anchors are usually shorter than half the length of the spicule, rarely a little 

 longer. They are 52-70 yu long and 52-59 m broad. The proportion of their 

 length to their breadth is 100 to 84-104, on an average 100 : 95. The anchor- 

 teeth are strongly curved in their basal part, but only slightly curved in their 

 distal part. Some?* of these spicules have irregular anchors, composed of teeth 

 unequal in length. 



The micramphidiscs (Plate 94, figs. 5-13), particularly the larger ones, are 

 very abundant. They are 31-106 ^ long, most frequently about 84 /j. The 

 shaft is straight, centrotyle, and 1.5-4 // thick. The central tyle is 3.5-5.5 m 

 in transverse diameter, that is 0.6-2.6 m more than the adjacent parts of the 

 shaft. An irregular verticil of spines, up to about 1 ix long, arises from the 



