COLLECTED ON THE ' CHALLENGER ' EXPEDITION. 353 



18. C. POLYMORPH!, n. Sp.f 



Char. Zoarium irregularly branched ; branches tapering, short. 

 Zooecia very confusedly disposed ; surface coarsely granular. 

 Orifice (primary) circular, widely emarginate ; afterwards the 

 peristome becomes much thickened and raised so as to conceal 

 the primary mouth. Three or four acute curved denticles within 

 the peristome, which, in this stage, is unarmed. In other zooecia 

 the labial sinus becomes fissured, and eventually converted more 

 or less completely into a suboral pore, whilst in front the peri- 

 stome forms a prominent tubercular eminence, supporting on the 

 side overlooking the fissure a large avicularium, with a blunt 

 triangular mandible and toothed beak. A few interspersed avi- 

 cularia on low horizontal eminences, with a spatulate mandible 

 (often truncated) and bifid beak. Ooecia erect or subrecumbent, 

 globose ; surface finely granular. 



Hob. St. 260*. Off Honolulu, 20- 40 fms. 



18a. Tar. a. DISCOIDEA.J 



Char. Zoarium (in single specimen) discoid, unilamellar, at- 

 tached only at the centre. Zooecia at the growing edge ventri- 

 cose, surface granular, entire ; primary orifice suborbicular or 

 elliptical, with a minute three-toothed process within the lower 

 border. This latter is gradually developed into a large preoral 

 rostrum placed to one side, at the base of which is a small labial 

 sinus, and on the posterior face a large avicularium with a duck- 

 bill-shaped mandible and toothed beak, beyond which, in the older 

 zooecia, the rostrum is produced in the form of a strong conical 

 solid spine. A few interspersed recumbent subimmersed avicu- 

 laria, with a long lanceolate mandible and non-serrated beak. 

 Hob. St. 186. Lat. 10° 30' S., long. 142° 18' E., 8 fms. 



19. C. TDP.ERCULATA, n. Sp.§ 



Char. Zoarium massive, tuberculated. Zooecia erect, in groups 

 of several together. Orifice arcuate or sub quadrangular, slightly 

 notched or sinuated below ; peristome thick. Preoral rostrum 

 yery short, conical, with a minute avicularium near the summit. 

 A few large interspersed avicularia on elevated hollow processes, 

 with a broad, spear-shaped, obtuse mandible, which does not 

 shut down within the beak. 



Hal. Port Jackson, 2-10 fms. 



t " Ohall. Eep." pi. xxx. fig. 11. 



J " Chall. Eep." pi. xxx. fig. 8. § " Chall. Eep." pi. xxviii. fig. 9. 



