WITH NOTES ON THE WEST INDIAN SPECIES, 



325 



EXPLANATION OF PLATES XXVI— XXXIL 



The material was chiefly preserved in Mayer's Picro-Nitric solution and in a Chrome- 

 Osmic mixture which was recommended to me specially for preserving Enteropneusta by 

 Mr J. P. Hill. It gave excellent results and is the most reliable fluid for unique specimens. 

 The following proportions are employed : — 



Chromic Acid 1°/^ — 100 c.c. 

 Osmic Acid 1°/^ — 2 c.c. 



Objects may be left in this fluid for 12 hours (overnight) and then washed out in water. 

 Specimens preserved in 4 — 5 formalin are useful for dissection. 



REFERENCE LETTERS. 



a. 



Artefact. 



gp^- 



First gill-pouch. 



adv. 



Advelient dermal vessel of proboscis. 



gpc. 



Coecum of gill-pouch. 



ag. 



Accessory gonads. 



gs. 



Gill-sUt. 



an. 



Anterior neuropore. 



g,\ 



First gill-slit. 



b. 



Blood-space. 



h. 



Pericardium (not in PI. XXVI. Fig. oA, q.v.) 



bm. 



Basement membrane. 



kg. 



Hind-gut. 



hr. 



Branchial sac. 



i. 



Intestine. 



bs. 



Central blood sinus. 



ic. 



Inner circular muscles of collar. 



c. 



Collar coelom. 



iec. 



Intra-epidermal canal. 



ca. 



Ciliated apparatus (ciliated grooves of intestine). 



a. 



Inner longitudinal muscles of collar. 



cc. 



Collar canal. 



I. 



Hepatic saccule. 



cf- 



Collar funnel. 



Ig. 



Lateral gonad. 



cm. 



Circular muscles. 



Im. 



Longitudinal muscles. 



cp. 



Collar pore. 



Ip. 



Left proboscis pore. 



ct. 



Fold in wall of collar canal. 



Ips. 



Lateral pouch of stomochord. 



dgp. 



Dorsal diverticulum of gill-pouch. 



Is. 



Lateral septum. 



dn. 



Dorsal nerve-cord. 



Iv. 



Lateral vessel. 



dp. 



Dermal pit. 



nic. 



Medullary canal or cord (collar nerve-cord). 



drv. 



Dorsal recurrent dermal vessel of proboscis. 



mg. 



Medial gonad. 



ds. 



Dorsal septum (Mesentery in PI. xxx. Fig. 32). 



7ns. 



Median septum of proboscis. 



dv. 



Dorsal vessel. 



oc. 



Outer circular muscles of collar. 



ei. 



Epidermal involution. 



oe. 



Oesophagus. 



ep. 



Epidermis. 



ol. 



Outer longitudinal muscles of collar. 



epb. 



Epibranchial tract. 



P- 



Proboscis coelom. 



ep.e\ 

 ep.i.\ 



Outer and inner epidermis of collar-flap. 



pb. 

 pbc. 



Parabranchial ridge. 



Postbranchial canal. 



ept. 



Epidermal tract. 



pc. 



End- vesicle or end-sac of proboscis (Eichelpforte) 



et. 



Anterior epidermal involution (Epidermistasche). 



ph. 



Perihaemal cavity. 



ev. 



Efferent vessels of proboscis. 



pnp. 



Posterior neuropore. 



9- 



Gonads. 



pph. 



Peripharyngeal cavity. 



gd. 



Genital duct. 



ptv. 



Post-trematic portion of end-sac (also pc). 



gl. 



Glomerulus. 



py- 



Pygoohord. 



