* 1873.) 
Possessing chitinous outgrowths, 
either as scales or plates, hairs or 
spines, the latter being secreted by 
setigerous follicles. 
Cuticle perforated by minute pores. 
Perivisceral cavity lined in some 
cases by delicate ciliated membranes. 
An extensive vascular system, con- 
taining a colored fluid representing 
the pseudo-heemal system. The cor- 
puscular nutritive true blood is con- 
tained usually in the perivisceral 
cavity alone, and in a few instances 
is found penetrating the pseudo-he- 
mal system. 
Embryos distinctly transversely 
segmented. In some cases attached 
by caudal portion at a later stage. 
In some groups intestine having no 
anal outlet. 
Sedentary Annelids. 
Usually having body divided into 
regions, the thoracic and caudal. 
Springing from the head, in many, 
two arms, often twisted into a closely 
wound spiral, and sustaining ciliated 
cirri. 
Encireling the head, or base of 
arms, a flaring membrane split upon 
the sides, and notched, in the dorsal 
and ventral median line. 
Mouth unarmed. 
Mostly fabricators of sand tubes 
which invests the body. 
Gephryreans. 
Never definitely segmented. Anus 
opening anteriorly in many. 
oll 
[Morse, 
Possessing chitinous and calcareous 
outgrowths, as scales or plates, and 
chitinous outgrowths, as hairs or 
spines, the latter being secreted by 
setigerous follicles. 
Cuticle perforated by minute pores. 
Perivisceral cavity lined by delicate 
ciliated membranes. 
An extensive vascular system, 
which may represent the pseudo-hz- 
mal system. The corpuseular nutri- 
tive true blood is contained in the 
perivisceral cavity alone. 
Embryos distinctly transversely 
segmented. In most cases attached 
by caudal portion at a later stage. 
In some groups intestine having no 
anal outlet. 
Having body divided into two 
regions, the thoracic and caudal. 
Springing from the head two arms, 
often twisted into a closely wound 
spiral, and sustaining ciliated cirri. 
Encircling the head and arms, a 
flaring membrane split upon the sides, 
and often notched in the dorsal and 
ventral median line. 
Mouth unarmed. 
One, Lingula pyramidata, fabricates 
a sand tube, which invests the body. 
Never definitely segmented. Anus, 
when present, opening anteriorly. 
