Boone, Annelida, Cruises of "Alva" 87 



Eurythoe complanata, Langerhans, P., Nova Acta Acad. Caesa- 

 reae Leop. Carol., 1881, vol. XLII, p. 108. — Chamberlin, R. 

 v., Mem. Mus. Comp. Zool., 1919, vol. XLVIII, p. 28, pi. 14, 

 figs. 3-8-9, (with extensive synonymy). — Fauvel, P., Mem. 

 of the Indian Mus. Calcutta, vol. XII, No. 1, 1932, p. 45, (with 

 additional synonymy) . 



Family: HESIONIDAE 



Genus: HESIONE Savigny 



Hesione pantherina Risso 



■f 

 Plate 28 



Type : Risso's type came from the Mediterranean Sea, in the 

 vicinity of Nice, littoral zone, and is deposited in the municipal 

 museum in Nice. 



Distribution: This species, originally described from the 

 Mediterranean Sea, has since been many times reported from the 

 littoral zone of the tropicopolitan areas of the Atlantic, Pacific and 

 Indian Oceans. The "Alva" specimen appears to be the first record 

 of this species from the Society Islands. 



Material examined : One very fine specimen, taken on Venus 

 Point Reef, Tahiti, Society Islands, August 15, 1931. 



Technical description : The praestomium is triangular, nine- 

 tenths as long as wide proximally with the distal apex narrowed 

 and rounded anteriorly. The dorsal surface of the head is defined 

 into three lobes, the anterior median lobe and two lateral lobes, 

 these being defined by a pair of curved depressions, one on each 

 side, which extend inward from the base of the tentacle toward the 

 center, but continue caudad separately, defining a median poste- 

 rior area, which is separated by a short transverse sulcus from 

 the anterior median lobe. There is a single small tentacle which 

 arises lateroventrad, at the outer terminus of the above-described 

 sulcus ; this tentacle is composed of about seven incomplete annuli, 

 is a distally subacute and extends to the anterior margin of the 

 praestomium. Two pairs of eyes are present, the anterior pair 

 being the large, subcircular and the posterior pair ovoid. The 

 eyes are all small, sessile, blackish-brown pigment spots. 



