1899.] NATURAL SCIENCES OF PHILADELPHIA. 521 



Placobranchus gracilis ^ea!^e. 



One specimen. Apia reef. June, under a stone. BufF- 

 colored, with green eye-like spots, surrounded with bright black 

 rims. Epipodia reflected over the back and striped internally 

 with longitudinal bright green ridges. Edges of epipodia and 

 frontal veil and tentacles violet colored. On a prominence 

 between the tentacles are two distinct black eyes. 

 Bornella Gray. 



I obtained two species of this genus at Apia. The first is B. 

 arborescens, described by Pease in the Amer. Jour, of Conch., 

 1870-71, p. 302). I have nothing to add to his account except 

 that the red coloring is rather brighter than in his figure. The 

 second I somewhat doubtfully identify with B. Hancockana 

 (Kelaart, in Annals and Magazine of Nat. History, 1859, Vol. 

 IV). In life the body was subpellucid, and the back mottled with 

 yellow. Over the mouth are two stellate processes with about ten 

 rays each. The rhinophores are greenish and retractile into four- 

 fingered sheaths. There are five pairs of cerata, four containing 

 hepatic diverticula, and all bearing branchiae. The three anterior 

 cerata are trifid, the two posterior bifid. There are two black eyes 

 under the skin just in front of the rhinophores. The animal is 

 very active and crawls and swims rapidly. 



Elysia nigropunctata Pse. 



A single specimen captured at Apia seems midway between the 

 species called by Pease Plerogastron (= Elijsia) marginatus and 

 Pterogastron nigropunctatus. The body was greenish, with black 

 and white spots, as in his figure of the latter (Amer. Jour, of 

 Conch., 1870-71, p. 304), but the lateral lobes are edged with a 

 single line of orange, somewhat less conspicuous than in his figure 

 of the former. On the whole, I think the animal should be called 

 Elysia nigropimctata. 

 Elysia Hendersoni n. sp. PI. XIX, fig. 4. 



In July I found twelve specimens of an Elysia on green seaweed 

 at Manono, which do not appear to me to be referable to any 

 species of which I have seen the description. The outer surface of 

 the animal is greenish, with yellowish markings, and resembles a 

 piece of seaweed sprinkled with sand. The interior of the 



