54 THE BRITISH NUDIBBANCHIATE MOLLUSCA. 



Genus 19. ANTIOPA, Alder and Hancock. 



Branchiae arranged on a pallia! ridge on the sides of the back and in front of the head. 

 Dorsal tentacles laminated, united by a semicircular crest. Oral tentacles with or without a 

 veil. Fain. 3, PI. 43. 



Tongue broad, with numerous lateral spines and a central one, all simple. Corneous jaws. 



1. A. cristata, Bella Chiaje. Transparent buff-coloured or white; branchiae ovate-oblong, inflated, 



with a slender brown central vessel furcated above, the apices of a brilliant opaline blue ; 

 dorsal tentacles strongly laminated. Length li inch. PL 44, figs. 1 — 7. 



2. A. hyalina, A. and H. Pellucid, yellowish with brown markings down the middle of the back; 



branchiae elliptical, tuberculated, hyaline, with the central vessel fulvous ; dorsal tentacles 

 obtuse, obscurely laminated ; oral tentacles united by a narrow veil. Length ^ inch. PL 

 k%figs. 8—12. 



