jVIAdeepoeaeia of the deep sea. 335 



'Deep-sea Corals,' No. 4, Illustrated Catalogue, &c., 1871, of this coral, has enabled 

 me to place it amongst the fauna of the eastern Atlantic. 



Section RUGOSA. 



Family CyathaxonidsB. 



Genus Gutnia, Duncan. 



The corallum is simple and long. The wall is thick and solid. The septa are well 

 developed, lamellar, unequal, and are continuous from the base to the calice. There 

 are four systems of septa ; and one primary septum is longer and larger than the others. 

 The columella is essential, and is attached to the larger septa. 



There is no endotheca. 



The costsB are visible on the growth-rings of the outside of the wall. There is an 

 epitheca. 



GuYNiA ANNULATA, spec. nov. (Plate XLVII. figs. 9-16.) 



The corallum is long, cylindrical, and narrow. It is sometimes curved. The accretion- 

 ridges are well developed and regular, and are marked with prominent short spinicles, 

 laminae, or granules, which correspond with the costae. The epitheca which ornaments 

 the ridges is delicate. The costse extend over the whole length of the corallum, and 

 usually exist as fiat bands between the close and rather wavy accretion-ridges. There 

 are foiu- principal septa, one of which is larger than the others, at the calice. The four 

 secondary septa are often as large as the primary ; but the eight tertiary septa are almost 

 rudimentary. There are four systems of septa and three cycles in each. None are 

 exsert. The columella is stout, cylindrical, deeply seated in the calice, and adheres to 

 the larger septa. The interseptal loculi are large ; and the transverse outline of the 

 corallum is sometimes rather angular. The length of the perfect corallum probably 

 f inch, the breadth -^ inch. 



Locality: Adventure bank, in 92 fathoms. It is frequently found adherent by its 

 side to shells and foreign bodies. 



Longitudinal sections prove the absence of endotheca. 



In three specimens there were evidences of an hexameral septal arrangement. One 

 had the octomeral at the base, but the hexameral at the calicular end. A transverse 

 section midway showed the eight large septa ; so that there must have been an arrest of 

 development during growth, and the specimen illustrates the formation of the neozoic 

 type from the rugose. A second specimen, when scraped down, showed the union of a 

 septum with another ; and as this occurred in two instances, seen in one and inferred in 

 another, the arrest of development was accounted for. 



The interesting affinity of this form with the rugose coral Haplophyllia paradoxa 

 VOL. VIII. — PAKT V. March, 1^1'^. 3 b 



