COLLECTED ON THE ' CHALLENGER ' EXPEDITION. 349 



straight, "with a minute 3-toothed pectinate process within it. 

 A short pointed preoral rostrum, supporting on one side a small 

 avicularium, with a semicircular mandible. In the older parts 

 very numerous, large, interspersed prominent avicularia, with 

 lanceolate mandible pointing upwards, and simply channelled 

 beak. 



Hob. St. 260*. Off Honolulu, 18 fms. 



Differs from C. tridenticulata in the much smaller size of the 

 internal denticles, which rather resemble a minute 3-toothed 

 comb, and in the almost universal presence, on the front of the 

 older zocecia, of a prominent avicularium with a lanceolate 

 mandible and simply channelled non-serrated beak. 



9. C. IMBELLIS.t 



Char. Zoarium lamellar, flexuose, thin. Zocecia distinct, erect, 

 free above, ventricose and immersed below ; surface finely pitted. 

 Orifice arcuate, or subtriangular or suborbicular, about 0" - 006 

 wide ; peristome slightly thickened, a small avicularium in front 

 just within the border. A few interspersed immersed avicularia, 

 with an elongate spatulate mandible. 



Hob. Off Bahia, 10-20 fms. 



Only a single specimen, apparently old and dead. 



10. C. etjdis, n. sp.J 



Char. Zoarium (in a single specimen) consisting of a short, 

 thick, cylindrical stem rising from a broad base and dividing into 

 two rounded lobes. Aspect rugose and coarse. Zocecia com- 

 pletely immersed and very confusedly heaped together. Orifice 

 subquadrangular, large (nearly 0"*01 wide), depressed. Preoral 

 rostrum in the ordinary zocecia merely a tubercle supporting an 

 oval avicularium, with a blunt elliptical mandible pointing down- 

 wards ; in the fertile zocecia the rostrum is developed into a 

 broad hollow process, from which a raised border passes back on 

 each side of the orifice to the sides of the ocecium. Ocecium 

 deeply immersed, having on the front a crescentic disk, marked 

 with radiating furrows. Yery numerous interspersed immersed 

 avicularia, lying in all positions, and of very various sizes, with a 

 broad short mandible, much contracted at the base. 



Sab. St. 320. Lat. 37° 17' S., long. 53° 52' W. j 600 fms., 

 hard ground. 



t " Chall. Eep." pi. xxix. fig. 10. 



\ " Chall. Eep." pi. xxviii. fig. 7. The operculum in C. rudis ispyriforni ; so 

 that it really belongs to the next section. 



LINN. JOUEN. — ZOOLOGY, VOL. XV. 28 



