CORONULA DIADEMA. 417 



sheath does not here project freely, and does not descend quite so close 

 to the basal membrane. 



Mouth. — The palpi are furnished with a row, extending along the 

 whole basal exterior margin, of very long upwardly pointing spines ; on 

 their upper edges there is a brush of small spines. The edge of the 

 labrum is clothed with extremely fine spines, and is furnished with a 

 few minute teeth. The mandibles have four teeth, and the lower 

 end is broadly rounded and coarsely spinose : the second and third 

 teeth are double at their points, and between the second and third, and 

 again between the third and fourth, there is a small intermediate tooth. 



Regarding the Cirri, I have nothing especial to remark. 



Geographical Distribution. — I have examined nine sets of specimens, 

 having localities attached to them : three from off New South Wales ; 

 two off the Cape of Good Hope ; two from the west coast of South 

 America; and two marked only "South Sea." Hence I am led to 

 conclude that this species is confined to the southern hemisphere, or if it 

 extends into the northern hemisphere, it is probably only in the Pacific 

 Ocean. I do not believe (though so stated in some works) that this 

 species occurs on the shores of Europe. It seems often to be as- 

 sociated with Tubicinella. Some specimens thus associated, sent by 

 Mr. Bennett to Professor Owen, were said to have been attached to the 

 Balcena australis. 



2. CORONULA DlADEMA. PI. 15, fig. 3, 3 Cl y 35: PL 16, 



%. 1, 2, 7. 



Lepas diadema. Linn. Systema Naturae, 1.767. 

 — — Chemnitz. Conch., vol. 8, Tab. 99, figs. 843, 844. 



Balantjs diadema. Bruguiere. Encyclop. Method., PI. 164, fig. 13, 



14 (1789). 

 Coronula — Be Blainville. Diet, des Sc. Nat. (1824), 



Tab. 117, fig. 4. 



— — Leach. Encyclop. Brit. Suppl., vol. hi, 1824. 



— — Chenu. Illust. Conch., Plate, fig. 3. 



— — Burmeister. Beitriige zur Naturgeschichte der 



Eankenfasser, 1834, Tab. 2, fig. 1—14, 18. 



Shell crown-shaped, with longitudinal convex ribs, having 

 their edges crenated ; orifice hexagonal: radii moderately 

 thick, very broad: terga absent or rudimentary. 



Hub. — Attached to whales, in the Arctic Seas ; United States and Great 

 Britain; Gulf-Stream, Atlantic Ocean; New Zealand (?). 



General Appearance. — As previously remarked, owing to the fulness 

 of the generic description, minute details on structure, excepting those 



27 



