18*79.] NATURAL SCIENCES OP PHILADELPHIA. 19 



third the size of the pedal ones, the commissure between them 

 measuring about one-third the length of each ganglion. 



III. FLABELLINA, Cuvier. 



Fldbettina, Cuvier, Regne An. ed. ii a , 1830, iii. p 55. Alder and Hancock, 

 Mon., Part VII. p. xxi. 1855. Trinchese, Rendic. della Acad, della 

 Sci. di Bologna, 7, 1874. R. Bergh, Beitr. znr Kenntn. d. Aeolidi- 

 aden, hi., Verb. d. K. K. Zool.-bot. Ges. in Wien, xxv. p. 647, 1875. 



Corpus sat elongatum, subcompressum. Rhinophoria perfo- 

 liata. Papillae (dorsales) non caducse, pedamentis brachioformibus 

 insertse. Podarium angulis tentaculatim productis. 



Margo masticatorius mandibular seriebus denticulorum prse- 

 ditus. Radula triseriata, dentibus medianis denticulati, latera- 

 libus interno margine denticulatis. Penis stylo armatus. 



As for the history of the denomination of this genus the reader 

 must be referred to my above cited paper. The Flabellinse have 

 nearest relation to the CalmseJ but differ by the perfoliate rhino- 

 phoria and in the denticulation of the lateral teeth. They show 

 an elongate, somewhat compressed form of the body ; perfoliated 

 rhinophoria; dorsal papillae caducous, inserted upon arm-shaped 

 foot-stalks the foot with produced anterior angles. The cutting 

 edges of the jaws with rows of small denticles. The tongue with 

 three series of teeth ; the median denticulated in the usual way, 

 the lateral ones only on the inner edge. The penis with a stylus 

 (as in the Calmse). 



To this genus belong: 



1. F. affinis (Gin.), Bergh, 1. c. p. 649, Taf. XV. f. 6-19; Taf. XVI. 1. 



3-4. M. Medit. 



2. F.flabellina (Ver.), M. Medit. 



3. F ianthina, Angas, M. Pacificum. 



4. F. ornata, Angas, M. Pacificum. 



5. F. JSfewcombi, Angas, M. Pacificum. 



6. F. iodinea (Cooper), M. Pacific, orient. 



1. Flabellina iodinea (Cooper), Plate I. f. 15 to 17; Plate II. f. 16. 



Aeolis (Phidiana?) iodinea, Cooper, Proc. Calif. Acad. ii. 1862, p. 

 205 ; 2 iii. 1863, p. 60. 



1 Cf. my above cited paper, 1. c. p. 643. 



2 "Rich, violet purple, narrow, wedge-sbaped, high in front, tapering to 

 an acute point behind, slightly constricted in five parts of the body corre- 

 sponding to divisions of the brauchise. Foot very narrow, slightly expanded. 



