CORONULA REGINjE. 419 



about half the thickness of the compartment, and consequently they 

 are separated from the plates (c" in fig. I and 7) on which the alae rest, 

 by large chambers (v in fig. 7), which extend up to nearly the apices 

 of the compartments : the extent, however, to which the upper ends of 

 these chambers have been solidly filled up, varies a little. The sinuous 

 plates forming the main portion of the compound radii are rather 

 thinner and closer together than in C. balcenaris. The alae are thick, 

 being thickest in the middle part, and there equal the radii in thickness ; 

 their lower margins are very short compared with their upper margins, 

 hence they are almost wedge-formed. 



Mouth. — The teeth and fine hairs on the labrum are sometimes ob- 

 scure, and sometimes plain : close outside the bottom of the medial notch, 

 there is a small hard prominence. The palpi are broad ; on their basal 

 exterior margins there is a short row of spines, which do not equal in 

 length the width of the palpi, and therefore are not so long as in C. 

 balcenaris. The mandibles have five main teeth, of which the second 

 and third show only an obscure rudiment of being double ; between 

 these two teeth, and between the third and fourth tooth, there is a 

 small intermediate tooth : the inferior angle is narrow, rounded, and 

 spinose. The extremity of the apodeme of the maxillae is expanded. 



Cirri. — I have only to remark, that the pedicel of the first cirrus is 

 extremely broad, and that the rami are set on in an unusually crooked 

 manner : the basal segment of the shorter and broader ramus of this 

 cirrus has its dorsal surface produced into a plate fringed with very 

 fine hairs. 



Geographical Distribution. — I have received only four specimens 

 with certain localities attached to them : namely, the Arctic Seas of 

 Scandinavia ; the coast of the United States, and of Britain ; and the 

 Gulf-Stream. There is also a specimen in the British Museum, sent 

 by Mr. Stephenson, mingled with shells of Mollusca from New Zealand ; 

 but a Coronula, procured from a floating whale in the early part of the 

 outward voyage, might so easily be sent home with specimens subse- 

 quently collected in another county, that I do not as yet fully admit 

 that this species is an inhabitant of the Southern Pacific Ocean : I am 

 less willing to admit this, from suspecting that C. regince in the Pacific, 

 replaces the C. diadema of our Northern Seas. 



3. CORONULA REGIN^. PI. 15; fig. 5 : PI. 16, fig. 4. 



Shell globulo-conical or depressed, with longitudinal, much 



flattened ribs, having their edges crenated, and their surfaces 



striated and granulated ; orifice hexagonal : radii thin, not 



exceeding one fifth of the thickness of a compartment : terga 



absent. 



Hab. — Attached to whales, Pacific Ocean ; Mus. Cuming, Stutchbury, and 

 Darwin. 



