o'donoghue : nudibeanchiate mollusca. 149 



not referring to the " foliaceous outgrowths " as Heath appears 

 to suggest. He is using a well-known technical description of the 

 clavus of the rhinophore when he says it is " foliate ". This is the 

 " white papilla " with a " lamellar structure ". The species bears on 

 the cowl two foliaceous outgrowths which are extremely modified 

 rhinophore stalks, and at the antero-median corner of each of these 

 is a small, retractile, foliate clavus with six or seven very low leaves, 

 which when partially extended appears superficially to be somewhat 

 spiral in shape. When this is fully retracted the whole clavus and 

 sheath simply forms a tiny thickening about 2-2-5 mm. by 1-1-5 mm. 

 on the edge of the large appendage, and is very easily missed. It 

 seems highly probable that Heath overlooked tliis structure, and it 

 is interesting to note in this connexion that he actually figures a 

 nerve (pi. xi, c4), calling it the " tentacular nerve ", which, if he had 

 followed it completely, would have been found to send its main 

 branch to the clavus. That this organ can readily escape notice 

 I know from my own experience, since in my description of the 

 external characters of this species I also overlooked this tiny clavus. 



It would appear, then, that C. dalli cannot be admitted as a valid 

 species without confirmation, and with this view Professor F. M. 

 MacFarland is in agreement for, at any rate, some of the reasons 

 given above. 



Kjerschow-Agersborg in 1919 (9, p. 269) and again in 1921 

 (10, p. 222) deals with the animal from Puget Sound as Melihe 

 leonina. The present writer in the same year as the latter also 

 furnished a description of this species from Vancouver Island 

 (11, p. 192), using the name Chiorcera leonina, which was employed 

 again later (12, p. 165). 



The genus Melihe was established by Rang in 1829 (13, pp. 129- 

 130), and the same term was employed by Bergh in 1875 (2, pp. 362- 

 376) and in a series of subsequent papers, particularly one in 1907, 

 where he actually refers the Chiorcera leonina of Gould to this genus 

 (4, p. 96). 



In my previous papers I had not access to the complete literature 

 of Bergh, and so I placed the form back in the genus Chiorcerd. 

 Ee-examination of the question in the light of the further details 

 adduced by Kjerschow-Agersborg, however, leads me to think that 

 there is no valid reason why this species should not be referred to 

 the genus Melihe, the name of which has priority over Chiorcera, 

 and with this conclusion Professor F. M. MacFarland informs me 

 he is in entire agreement. 



The family Teth5rmelibid8e, so far as at present recorded, is repre- 

 sented by one species from the area under consideration. This 

 form is widely distributed from South-eastern Alaska down to 

 Santa Barbara, and has probably been taken from a wider range of 

 localities than anv other Nudibranch on the coast. 



