3ho 



62 THE GREAT BARRIER REEF. 



CHROMO PLATE XIII. 



GREAT BARRIER REEF MOLLUSCA AND PLANARIANS. 



Fig. I. — Flat-worm or Planarian, Psnidoccros Keiitii, n.sp., von Graff (////;-«). Life size and colour 

 Fig. 2. — Fiat-worm or Planarian, Psr/irfocrros dimidiatus, n.sp., von Graff (infra). Life size and 



colour. 

 Fig. 3. — Blue-spotted Octopus, Octopus pidus {infra). Life size and colour. 

 Fig. 4. — Sea-hare, Aplysia sp. Life size and colour. 

 Fig. 5. — Flat-worm or Planarian, Prostheccra^ns flavoniacnlafus, n.sp., von Graff [infra). Life size 



and colour. 

 Fig. 6. — Nudibranchiate Mollusc, Doris sp. Life size and colour. 

 Fig. 7. — Nudibranchiate Mollusc, Doris sp. Life size and colour. 

 Fig. 8. -Nudibranchiate Mollusc. ? gen. ? sp. Life size and colour. 

 Fig. 9. — Nudibranchiate Mollusc, Anctila sp. Life size and colour. 



Fig. 10.— Group of "Frilled" or " Furbelow" Clams, Tridacna conifrrssa, p. 12. Arranged to 

 show onl}' the gaping valves, and the diversified hues of the brilliantly-tinted mantle 

 folds ; natural size. 



The author is indebted to Professor G. B. Howes for much assistance in the iden- 

 tification of the organisms depicted on the upper portion of this plate. The brilliant 

 coloured Planarians represented by Figs. Nos. i, 2, 5, proved, on reference, through Professor 

 Howes, to Professor Ludwig von Graff of Graz (the recognised authority on this group), to 

 be in all instances new species, the author's thanks are here tendered for the names bestowed. 

 Nos. I and 5 were collected by the author crawling among growing Madreporae in the Albany 

 Pass and at Thursday Island respectively, and No. 2, under similar conditions, in the vicinity 

 of the Palm Islands. 



The remaining most notable species is the blue-spotted Octopus, delineated by Fig. 3. 

 This has been identified for the author, through Professor Howes, with the Octopus pictus of 

 Brock, of which Mr. W. E. Hoyle has described a variety, under the title of O. pictus 

 var. fasciatus, in his monograph on the Cliallcngcr Cephalopoda. The illustration here 

 given is of interest, since it represents the first occasion on which the natural colours of 

 this species have been recorded. As originally described by Dr. Brock (Zeitschrift fur 

 Wissenschaftliche Zoologie, Bd. 36, 1882), the animal (described from a spirit-preserved 

 specimen) was said to be yellowish, with blackish-brown spots. In life, these spots are 

 suffused with glowing shades of the richest ultramarine-blue, each exhibiting for the most 

 part a lighter central area and a darker annular border. The species was collected by the 

 author towards the southern limits of the Barrier district, and on the Victorian coast-line. 



