■338 SIK SIDNEY r. HAEMER ON 
Las almost become biserial, while its basal het«rozooecia have acquired the 
full vibracuiar form, so as closely to resemble those of Scrupocellaria. 
A. kirkpatricki from Marion Id., A. gaussi from the Antarctic, and A. crassi- 
marginata from off Buenos Aires all come from localities within the range of 
Amastigia and apparently outside that of Scrupocellaria ; and their distri- 
bution supports the conclusion I have come to on other grounds as to their 
generic position. 
The vibraculum (fig. 47) possesses a rootlet-foramen of the usual kind, 
■situated opposite the proximal end of the muscular mass and given off from 
a small chamber separated by a calcareous wall from the rest of the vibraculum. 
The figure shows what appears to be another rounded chamber on the distal 
side of the rootlet-chamber. In side view this is seen to be continuous with 
the main vibracuiar chamber, and it is really the foot hj which the vibraculum 
is connected with the proximal end of its zooecium, a communication-pore 
■occurring in the wall which separates it from the zooecium. 
9. Amastigia gaussi {Kluge). 
Scrupocellaria gaussi, Kluge, 1914, p. 609, pi. 27. figs. 3, 4. Antarctic. 
Closely allied to A. kirkpatricki, and differing from it mainly in possessing 
a scutum, and in being 2-5-serial. 
10. Amastigia solida [Kluge). 
Scrupocellaria solida, Kluge, 1914, p. 611, pi. 27. figs. 7, 8. Antarctic, 350-385 
metres. 
Unjointed, 3-serial. Stalk of scutum connected with the middle of its 
lamina, which is lobed externally. Frontal avicularia occur, but marginal 
avicularia are not described. Basal avicularia paired, directed transversely 
inwards, the rostrum rather more vibraculoid than in the last species. 
Median zocecia reduced on the basal surface. 
11. Amastigia Antarctica {Kluge). 
Anderssonia antarctica, Kluge, 1914, p. 618, pi. 33. figs. 3. 4. Antarctic, 76-170 
metres. 
Unjointed, 6-8-serial. Scutum and spines wanting, the opesia with 
■straight lateral margins. The marginal zooecia face outwards, and they form 
the whole of the basal surface. Frontal avicularia present. The lateral 
avicularia described appear to be morphologically basal avicularia, since they 
are placed on the proximal and not on the distal ends of the zocecia. They 
are large and are arranged alternately on the basal surface, the rostrum 
directed obliquely proximally and being linear distally. A rootlet-foramen 
is present, a structure which seems to decide the question that these are basal 
heterozooficia. 
This species differs from the others described by Kluge in the absence of 
spines and scuta ; and in these respects it has a considerable resemblance to 
