HOLASCELLA ANCORATA. 
41 
spined, and with thin only slightly spined, distal rays occur among both. The 
distal rays of the hypodermals appear to attain a greater length than the distal 
rays of the hypogastrals, the former being usually over, the latter under, 400 n 
long. 
The few root-tuft anchors observed are monactines. Their axial cross lies 
in their terminal anchor-tyle. The shaft is covered with very irregularly dis- 
tributed, backwardly directed spines 17 n thick just above the terminal anchor- 
tyle. The terminal anchor-tyle is similar to that of Holascella taraxacum. It 
is, with the spines, 57-65 n broad and 74-90 n long. Its spines, the anchor- 
teeth, are very irregular. 
The microoxyhexactines (Plate 23 , fig. 8) measure 112-195 m in total diame- 
ter. Their rays are regularly arranged, in the same spicule fairly equal, straight, 
conic, pointed, 55-105 n long and 3-5 n thick at the base. Their length is not 
in proportion to their basal thickness, the shorter rays of smaller microoxyhex- 
actines being often thicker than the longer rays of larger ones. The rays are 
rather sparsely spined. The spines are sharp, not over 1 m long, and directed 
obliquely backwards. 
The onychomicroscleres (Plate 23 , figs. 10b, 11 , 14b, 15, 16) measure 65-90 n 
in total diameter, and have one to three end-rays. Many are microonychhex- 
asters with only one end-ray on all the main-rays. Others are hemionychhex- 
asters, with one end-ray on some, and two or, rarely, three end-rays on the other 
main-rays. A few are true onychhexasters with two to three encl-rays on each 
main-ray. The main-rays are regularly arranged and, in the same spicule, 
fairly equal. They are cylindrical, smooth, about 5 n long and 1.5-2 n thick. 
The end-rays are straight or only slightly curved, 28-50 n long, conic, at the 
base about 1 n thick, and at the end 0.5-0. 8 n. They bear exceedingly minute 
spines along their length, and at their end there are several, usually three or 
four, large, more or less vertical spines. These terminal spines are not over 
7 (1 long, very slender, and curved, either simply, concave to the centre of the 
spicule, or in an S-shaped manner. When two or three end-rays arise from a 
main-ray, they enclose angles of 30° to 40° with its continuation; when there is 
only one end-ray it lies in the continuation of the main-ray, and usually passes 
into it so gradually that main- and end-ray together appear as a simple, conic 
hexactine ray. Sometimes a slight irregular thickening or change of direction 
indicates the point where the main-ray passes into the end-ray. Such simple 
rays are 33-35 m long. 
The discomicroscleres (Plate 23 , figs. 5-7, 10a, 14a, 17-25) measure 130-220 m 
