92 Proceedings of the Royal Irish Academy. 



In addition to these there are often forms which are intermediate between 

 types (a) and (i) ; but these cannot be regarded as constituting a distinct 

 tjTpe. 



As we have already pointed out, the branching, as shown in this specimen, 

 is not of a character of sufficient value for speciiic determination. We would 

 therefore suggest merging it into the older species S. aurantiaca. 



Locality. — Ceylon Sea-. 



In the Littoral Collection of the Indian Museum, Calcutta, there is a very 

 long, simple, fiagelliform colony which has unfortunately been broken into 

 five pieces. The attachment is broken off, but very near the base, as is 

 evident from the absence of verrucae at the present basal portion. The total 

 length of the colony is over 112 cm. The diameter near the base (without 

 verrucae) is 3 mm. ; about midway it is 2 mm., while near the tip it is 1 mm. ; 

 so that the tapering is very slight. 



The coenenchyma is very smooth,' and is about O'o mm. in thickness 

 throughout the entire length of the colony. 



The general colour is brick-red ; but the anthocodiae are white. Near the 

 base of the colony there are no verrucae ; but after a short distance they 

 appear as if distributed all over the coenenchyma, and so simulate a spiral 

 arrangement; a distinct trace of two bare longitudinal spaces is, however, 

 clearly discernible ; these tend to disappear towards the tip of the colony, 

 owing to its extreme slenderness and the interlocking of the verrucae. 

 There are five rows near the base in each polyp-bearing tract ; but these 

 gradually diminish to two near the tip. The verrucae are small and 

 relatively distant. Near tlie base they have the form of short cylinders 

 (fig. 66) ; but are often flattened, owing to the collapse of the thin walls ; 

 they are about 1*25 mm. in height, and 075 mm. in diameter, and stand 

 almost perpendicularly. Towards tlie tip, however, they are smaller, more 

 retracted, and appear as small domes directed slightly upwards (fig. 67). 



The two main canals, corresponding to the two bare tracts, are clearly 

 visible in a cross-section. The other canals of the inner series are relatively 

 large. 



The axis is cylindrical, densely calcareous, and very brittle. It tapers in 

 a more marked degree than the colony itself. The colour of the lower part 

 is brown, but the core is white. There are deep longitudinal depressions on 

 the surface. The laminae are very thick, and may be seen with tlie naked 

 eye, in spite of the small diameter of the axis. 



The spicules (fig. 68) are quite typical of the species. 



Locality. — Laccadives, 30-50 fms. 



