REPORT ON THE NUDIBR ANCHI ATA . 
27 
Rizzolia, Trinchese. 
Rlzzolia, S. Trinchese, Rendic. dell’ Accad. di Bologna, 1879-80, p. 62. 
,, R. Bergh, Beitr. z. Kenntn. d. japan. Nudibr. I., Yerhandl. d. k. k. zool.-bot. Gesellscli. 
Wien, Bd. xxx., 1880, pp. 156-160. 
„ R. Bergh, Beitr. z. Kenntn. d. tEolidiaden, YI1., loc. cit., Bd. xxxii. 1882, pp. 37, 38. 
Corpus gracilius elongatum ; rhinophoria simplicia ; tentacula elongata ; papillae 
(dorsales) non caducae pedamentis humilibus impositae ; podarium antice angulis tenta- 
culatim productis. 
Margo masticatorius mandibularum serie denticulormn grossiorum. Radula pauci- 
dentata; dentibus uniseriatis, cuspidatis, denticulatis. 
Penis inermis. 
The genus Rizzolia was established by Trinchese in 187 7. In external characters it 
closely resembles Facelina, but is readily distinguished by the rhinophoria, which are 
plain (not perfoliated), and by the unarmed condition of the penis. 
Only the following species of the genus are known : — - 
1. Rizzolia 'per egrina (Ganelin). 
Mediterranean. 
2. Rizzolia modesta, Bergh. 
Japanese Sea. 
3. Rizzolia australis, n. sp. 
Pacific Ocean. 
Rizzolia australis, n. sp. (PI. IX. figs. 1-5). 
Habitat . — Pacific (Port Jackson). 
A single specimen was dredged, together with Chromodoris runcinata, from a depth 
of 2 to 10 fathoms, in Port Jackson, on the 17th April 1874. It was strongly 
hardened through having been preserved in alcohol, and had lost its dorsal papillae. 
The specimen measured 18 mm. long, by a breadth and height of about 4 mm. ; the 
height of the tentacles was 3‘5 mm., of the rhinophoria 3 mm., and the length of the 
edges of the foot 1'7 mm. ; the breadth of the sole of the foot was for the most part 2 mm. ; 
anteriorly it was somewhat larger, posteriorly somewhat narrower; the length of the tail quite 
4 mm. The colour throughout was of a yellowish-white, the anterior margin of the head was 
wdiitish, and from it a slender, whiter median line, discontinuous here and there, extended 
along the back; in front of and behind the rhinophoria there was a small transverse 
