88 SIR C. ELIOT ON NUDIBRANCHS [May 17, 



smaller numbers, being rare or completely absent from the shore 

 of the Bay at other times. 



Most of the animals were of a bright dark yellow with the black 

 liver showing more or less conspicuously through the ti-ansparent 

 integuments, but the colour ranges in exceptional cases from deep 

 ora,nge to almost colourless transparency. Many specimens were 

 infested with small light yellow copepoda found adhering to the 

 body, especially on and near the gills. 



The alcoholic specimens are of a more or less yellowish white. 

 The largest is 29 millimetres long, 12 high, and 8 broad, but, as a 

 rule, the back is proportionately broader. The whole body is smooth 

 and very soft. In most specimens the dorsal area is bounded by a 

 distinct lateral ridge. It is not visible behind the branchiae, but 

 extends from them to the front of the head, where, however, it is 

 not continuous but divided by a deep notch in the middle. In 

 several specimens this ridge is only clear in places and in a few 

 it is absent altogether. The rhinophores bear about ten perfolia- 

 tions and are set in such shallow pits that they can hardly be 

 called retractile. They are exposed in the alcoholic specimens. 

 The edges of the pits are smooth. The gill consists of from 20 

 to 34 leaflets*, set in a horseshoe or circle open behind, and placed 

 rather far back. The leaflets are flat and compressed and 

 decrease in size posteiioi'ly. The largest bear on each side about 

 ten lamellae, the smallest two or three. The whole appearance of 

 the branchial apparatus is quite unlike what is usual in the 

 circum-anal plumes of nudibranchs and recalls the prosobranch 

 gill. The foot is a narrow groove, but has a thin expanded 

 margin, including which the breadth is 6 mm. in large specimens. 

 The anterior margin of the foot is grooved and united with the 

 corners of the mouth, where it is joined by a second ridge, which 

 runs above it and apparently represents the tentacles. The tail 

 is bifid. 



The radula has a wide bare rhachis, and the formula varies from 

 about 11x10 + 2.0.2 + 10 to 15x14 + 2.0.2 + 14. The innermost 

 tooth is irregular in shape, but consists of a basal portion from 

 one end of which rises a more or less bent spine, while another 

 spine is more or less completely developed at the other end. The 

 second tooth is larger and is more distinctly bicuspid. The other 

 teeth are unicuspid, awl-like, and hardly bent ; and those nearer 

 the rhachis are rather stout, but they become slender towards 

 the end of the row. All the different forms of teeth are well 

 represented in Bergh's plates. In the nervous system the ganglia 

 are very distinct. The liver is large, black, and very soft. On its 

 anterior portion, and less detached from it than usual in the genus 

 (e. g., than in T. cocciiiea described above), are two yellowish 

 hermaphrodite glands of a somewhat irregular shape. Indeed, 

 though separable from the liver, they cannot be said to be separate 

 from it. This may be possibly due to the fact that the specimens 

 are in good condition, so that the membranes connecting the 



* The gills as rcpvest'iited in the Plate are not sufficichtlj' numerous. 



