40 
ON A NEW SPECIES OF ENTEROPNEUSTA, 
EXPLANATION OF PLATES. 
Reference Letters. 
ag. Projections of the anterior ends of the gill rows into the throat. 
av. Afferent skin vessels of proboscis, bps. Body of proboscis skeleton. 
bv. Limiting vessel of branchial region, cbs. Central blood space of pro- 
boscis, ccp. Prolongations of collar ccelom into the proboscis neck. cfw. 
Circular musculature of outer wall of anterior rim of collar, cjr. Ciliated 
groove, ch. " Chondroid tissue." ciw. Capillary net of inner wall of collar. 
cl. Cleft into which dorsal vessel opens, cm. Circular musculature of pro- 
boscis, cnc. Collar cord. cnp. Capillary net of proboscis, cnt. Capillary 
net of gill tongue. cm. Collar ccelom. cce'. Parts of collar ccelom into 
which collar pores open. cp. Covering pad. at. Inner layer of connective 
tissue of proboscis on the splanchnic epithelium, cv. Vessel connecting the 
two efferent proboscis vessels in the proboscis neck. cvc. Dorsal 
portion of circular vessel fold of collar, cvc'. Ventral plexus of circular 
vessel fold of collar. dgb. Dorsal gonad branches, div. Notochord. 
■dn. Dorsal nerve stem of trunk. dp. Dorsal proboscis pockets, dsc. 
Fibres of dorso-ventral muscle plate, dv. Dorsal vessel of trunk. ehep. 
Epithelium of liver sac. ep. Epidermis, epb. Epibranchial strand, eps. 
"End plate" of proboscis skeleton, epth. Epithelium of throat, epv. 
Efferent proboscis vessels, esv. Efferent proboscis skin vessels on front 
edge of heart bladder, g. Gonads, gap. Genital aperture, gc. Gill cleft. 
gg. Branchial canal, gl. Glomerulus, glm. Muscle fibres of glomerulus. 
gp. Gill pore. gs. Gill septum, gt. Gill tongue, gtb. Epithelium of gill 
tongue back. gtc. Gill tongue cavity, gw. Genital wings, h. Heart bladder. 
hep Cavity of liver sac. i. Intestine, its. Intermediate epithelial stripe 
of gill tongue. ifw. Musculature of fore wall of anterior rim of collar. 
ihn. Inner longitudinal musculature of collar. Urn '. Portion of same passing 
to the proboscis base. ivw. Infolding of ventral wall of heart bladder. 
ivw'. Anterior projection of the same into the cavity of heart bladder. 
hps. " Keel " of proboscis skeleton, lb. Anterior horn of blind sac lumen. 
lbs. Ventral blind sac of notochord. Ic. Limiting cushions between 
branchial canal and oesophagus. Ifw. Longitudinal musculature of outer 
wall of anterior rim of collar. llv. Lateral longitudinal vessel. Im. Longi- 
tudinal musculature of proboscis, lint. Longitudinal musculature of trunk. 
Imv. Longitudinal musculature of ventral wall of perihsemal spaces. Ips. 
"Legs" of proboscis skeleton. Ips'. "Nuclei" of proboscis skeleton. 
Is. Lateral septa of trunk, he. Longitudinal ventral vessel folds of inner 
wall of collar, mg. Median gonad branches, mgl Vessel passing from the 
median dorsal portion of the glomerulus. nf. Nerve fibre layer. nrg. 
Nerve fibre ring of proboscis neck. oav. Dorsal prolongation of the blood 
cleft in proboscis neck to form the afferent skin vessels, oe. (Esophagus. 
