166 On some new species of Nudihranckiate Mollusca, 



E. gracilis. — Body very slender, pellucid white. Dorsal tentacula 

 very long, linear, transparent, the upper portion opake white. 

 Oral tentacula of nearly equal length with the dorsal ones. 

 BranchicE long, slender, elliptic-oblong or nearly linear, of a 

 ginger-orange colour, with a minute ring of opake white near 

 the apex ; arranged in four or five clusters down each side of 

 the back. The first cluster contains seven papillae, the others 

 diminishing gradually in number. Foot long and slender, 

 extending considerably beyond the branchiae behind ; the ante- 

 rior angles much produced and tentacular. Length nearly 

 half an inch. 



Found under a stone between tide-marks. A very delicate and 

 graceful species. 



E. violacea. — Body short, white. Dorsal tentacula moderately 

 long, linear and obtuse, pale fawn-coloured. Oral tentacula 

 short, thickish and linear. Branchice elliptic-oblong, inflated, 

 semitransparent white, with a linear central vessel of a violet 

 colour, the apices encircled by a ring of opake golden yellow. 

 They are set in ten or twelve indistinct transverse rows of three 

 or four papillae each on the sides ; those next the back large, 

 long and inflated, the side ones very small. They extend for- 

 ward as far as the dorsal tentacula. Foot rather short, not 

 extending much beyond the branchiae, the front portion a little 

 enlarged and rounded. Length three-tenths of an inch. 



On a coralline from deep water. 



EXPLANATION OF PLATE IL 



Fig. 1. Venilia mucronifera, viewed from above. [The line on one side 



shows the natural size.] 

 Fig. 2. Portion of the under side of the same, showing the head and veil. 

 Fig. 3. Corneous jaws, upper side. 

 Fig. 4. The same, under side. 



a. Large plates united down the sides. 



b. Small plate. 



e. Arch supporting the corneous strap d. 



e. Cutting edge. 

 Fig> 5. Tongue. 



Fig. 6. Two spines of the same, more highly magnified. 

 Fig. 7. Stomach and gastro-vascular system. 



a. CEsophagus. 



b. Intestine leading to the anus. 



The junction of the vessels with the stomach, where marked with 

 dotted lines, could not be very distinctly made out. 

 Fig. 8. One of the branchial papillae. 



a. Central vessel connected with the gastro vascular system. 

 6. Larger vessel inclosing it and reaching the whole length of the 

 papilla. 

 Fig. 9. Central vessel, more highly magnified. 

 Fig. 10. Auditory capsule and otolites. 



