561 



Genus 18. Cheliuonura, Adamx. (Animal, pi. cxix. f. 16. 

 Shell, sp. 140. pi. cxxv. f. 167, 168.) 



Caput fasciculis tribus sericibus antice ornatum, postice in lobo 

 simplici lanceolato desinente ; oculi ? Pallium in filamentis longis 

 duobus postice prodnctiun. Pes ampins, antice lateribus acumi- 

 natis, postice rotundatus. 



Testa interna, minima, fragilis, tota aperta, margine dextro piano, 

 alato, postice acuto. 



Head with three small tufts of short silk in front, posteriorly 

 not bifurcated, but terminated by a single lanceolate tongue, 

 which is extended on the back. Mantle ending behind in two 

 long filaments like the tail of a swallow. Foot elevated on each 

 side, embracing the head and mantle, pointed at the sides in 

 front, rounded behind. Gill behind, on the right side. 



Shell hid in the thickness of the mantle, small, thin, very open, 

 scarcely spiral, with the right border ending in a point. 



M. Quoy observes that it swims by the aid of its mantle, 

 which was the case with a beautiful species obtained by me, also 

 in the Mauritius, but which became so mutilated as to afford but 

 the information that the species belonged to this genus, and was 

 distinct from C. kirundmma. The individual alluded to by 

 M. Quoy, which " had the back crossed with white, and all the 

 blue lines bordered with a line of gold," was probably a third 

 species. 



Genus 19. Doridium. (Animal, pi. cxix. f. 14.) 



Caput ovato-oblongum, antice retusum. Corpus oblongum, 

 postice truncatum ; angulis productis, elongatis, dilatatis s. fili- 

 formibus. Solea pedis in alam ovato-rotundam expansa, quaR 

 antice utrinque in lobulum carnosum minutum producta est. 



Testa nulla. 



Head ovately oblong, anteriorly retuse. Body oblong, pos- 

 teriorly truncated, the angles produced, elongated, dilated, or 

 filiform. Sides of the foot expanded into an ovately rounded 

 wing, which is produced anteriorly and on both sides into a 

 minute fleshy lobe. 



Shell none. 



Sp. 1. D. Meckelii, Belle Chiaje, Mem. 1. pp. 118, 133, 

 t. x. f. 1,2. Acera Meckelii, Philippi. Doridium membranaceum, 

 Meckel. 



D. dorso absque tuberculis lacteis ornatis. 



