44 ART. 1. — CHARLES ELIOT : 



lion due to the preserving fluid, but since they occur in all the 

 specimens and in the same positions perhaps they are natural. 

 When the cerata are in situ, no division into groups is discerni- 

 ble : there is merely a thick line of cerata along either side of 

 the back. But in a stripped small specimen eighteen cushions 

 are visible on either side and behind them a group of cerata on 

 the tail. The larger cushions bear 10 cerata each. 



The jaws have smooth undenticulate edges. The radula 

 consists of 18 pectmate teeth. They are bilobed but the curve 

 is unusually broad and undulating. The central cusp of each 

 tooth is large and there are as many as 65 long and very 

 transparent denticles on either side of it. In the smaller tooth the 

 number of lateral denticles is somewhat less. 



The external characters of this animal are rather doubtful 

 but the shape of the teeth is characteristic and different from 

 that of the other species described under the names of Aeolidiella 

 or Spurilla, two genera which is my opinion should be united. 



Pteraeolidia semperi Bergh. 



Three specimens labelled Bonin Is. and Misaki, Sagami. They 

 are long aeolids, 50-60 mm. in length and only 6-7 mm. broad, 

 of a uniform yellow as preserved and much bent. The oral 

 tentacles are large, the rhinophores perfoliate. The cerata are 

 set on 10-15 pairs of distinct fleshy flaps each of which bear 

 20-25 longish fusiform cerata. The jaws bear many rows of 

 knobs on the masticatory edge. The radula is a single row of 

 fairly broad horse- shoe teeth. The central cusp is strong and is 

 flanked by 11 denticles of which two or three arise from the 

 sides of the cusp not from the base of the tooth. No armature 

 was found on the genitalia. 



Fiona marina Forskol. 



See especially Bergh in Scientific Results of the Exploration of Alaska, I, 1879, pp. 142-144. 



Many specimens varying from 20 mm. to 25 mm. in length. 

 The details given below are taken from an average specimen 



