884 PROF. S. J. HICKSON ON THE 



Errina (Labiopora) nov.e zelandi^. (Facies Cooki.) 

 (PI. XOV. fig. 5 ; PL XCVI. figs. 10, 11, 12.) 



This specimen was obtained from the cable in Cook Straits 

 between the two islands of New Zealand, and was lent to 

 Pi'ofessor Benham by the Colonial Museum. According to 

 Professor Benham's notes, two specimens were obtained, one 

 being 50 mm. in height x 70 mm. across, and has six main 

 branches; the other is smaller, 30 mm. in height x 60 mm. 

 across. The general form of the coenosteum is ilabellate, the 

 main axis flattened but the branches cii-cular in section. The 

 branches do not anastomose in the specimen examined. Only a 

 small piece of one of these colonies was sent to me, and from 

 that I have drawn up the following notes. 



Colour : pure white. 

 • Surface and substance as in the other facies. 



Grooved spines not very crowded and not arranged in definite 

 rows, frequently in clusters with the grooves pointing in all 

 directions (fig. 12). 



Gasteropores evenly distributed on both sides of the flabellum, 

 without any lip or collar, 0'22 mm. in diameter. 



Large dactyl opores 0*06x0"08 mm. 



Small dactylopores I'are or veiy rare, 0*09 mm. in diameter. 



In comparing these four facies of the species, several points of 

 interest may be observed. 



They all agree in the general texture of the coenosteum, and 

 they all have a more or less flabellate form of growth. 



As regards the size of the hydrophytum as a whole, it is 

 impossible, owing to the broken condition of all the specimens 

 examined, to give exact measurements. A specimen of uncertain 

 facies in the Colonial Museum is 90 mm. x 70 mm. (according to 

 the MS. notes of Professor Benham), the specimen of the facies 

 " Cooki " was 50 mm. in height x 70 mm. in expanse. Judging 

 from these figures and from the size of the branches of the other 

 specimens, it seems probable that the normal size of a full-grown 

 specimen of the species is not more than 100 mm, x 100 mm., or 

 that, in words, it is a coral that does not normally attain a very 

 large size. 



Of the other chfiracters, perhaps the most important one to 

 consider is the dimorphism of the dactylopores, because this cha- 

 lucter has been used as a diagnostic character for the separation 

 of the genera Lahio2)ora and Errina. In the facies " Benhami " 

 and " Dendyi " there are clearly many small dactylopores lying 

 on the general surface of the coenosteum between the grooved 

 spines and distinct from the larger dactylopores. In the facies 

 " Ramosa'"' no such dactylopores could be found in the specimen 

 I examined (although Professor Benham says they are rare), and 

 in the facies " Cooki " they are certainly very rare. With the 

 many points of resemblance in form, colour, size of pores, etc. 

 between the two facies " Ramosa " and " Benhami," it would be 



