DESCRIPTION OF GENERA AND SPECIES. 



Tribe I. Hexactini^e. 



Family 1, Corallimorphid.e, R. Hertwig. 



Genus Corallimorplms, Moseley. 



Corallimorphus rigidus, Moseley. 



Amongst the supplementary material I have found the original specimen on which 

 Moseley formerly founded the species Corallimorphus rigidus. I had already mentioned 

 this on Moseley's authority in my earlier Report, though I had not myself seen it, 

 and had described from my own observation four more specimens, of which one, from 

 Station 157, agreed in all essential particulars with the three others from Station 146. 

 I am now in a position to confirm the statement that the three latter agree with 

 Moseley's specimen in form, in colour (of which traces only remain in spirit specimens), 

 and in the condition of the body-wall, — they exhibit no thickenings, but merely forty- 

 eight longitudinal furrows corresponding to the insertions of the mesenteries. Another 

 specimen, from Station 299, also agreeing with Moseley's type, is of interest, since, of 

 the twenty-four tentacles on the oral disc, one accessory tentacle of the first order is 

 duplicated, two little tentacles being planted close together. I have already described 

 a similar, though more strongly expressed, development of supernumerary tentacles 

 in Corallimorphus "profundus, so that it appears probable that the law of increase in 

 the tentacles of Corallimorphidse is not yet so definite as among other Actinias, and 

 allows of more variation than in other cases. 



Corallimorphus obtectus, n. sp. 



While the five last-named specimens agree with one another, that from Station 

 157, on which I chiefly based my former description, demands a separate position, so 

 that I now account it the representative of a new species to which I give the name 

 Corallimorphus obtectus, having regard to the buckle-like thickenings which cover the 

 insertions of the mesenteries. A further difference lies in its disc-like shape, due to the 

 relations of size between pedal and oral disc. Both are in this case of the same size, but 

 in Corallimorphus rigidus the former is considerably the smaller, producing a saucer- 

 shaped profile. The two species may be differentiated by the following diagnosis : — 



1. Corallimorphus rigidus. — Twenty-four tentacles are planted on the oral disc, 



(ZOOL. CHAI.L. EXP. — PART LXXIII. — 1888.) DdJJ 2 



