SPONGES FROM THE MERGUI ARCHIPELAGO. 



83 



rhaphidota, however, as this is by far the largest order, that, 

 as might be expected, the greatest number of species are to be 

 found ; while here we see the first four groups of the Henierid 

 family together with the groups " Fibulifera " and " Esperina," 

 and the Suberitida generally, most prominent in the matter of 

 quantity. 



That the orders Hexactixelleda and Calcarea should not in 

 any way be represented may be probably explained by the muddy 

 character of the locality, combined with the shallowness of the 

 water, which therefore must be continually kept in a state of 

 agitation by the tides and waves of the sea. 



In Tethya rnerguiensis and in the new genus AmorpTiinopsis 

 we have the addition of a trifid " zone-spicule " &c. to charac- 

 terize the former ; with the spiculation and excavating habit of a 

 sponge very much in appearance like Salichonclria panicea, 

 J ohnst., = Amorpliina, Schmidt, to establish the latter. 



But as the peculiarities of all the species have already been 

 stated in the foregoing descriptions, I need not repeat more here. 

 Suffice it, in conclusion, to state that there is a strong British 

 fades in the collection, somewhat modified by the difference in 

 locality. 



DESCRIPTION OF THE PLATES. 

 Plate V. 



Figs. 1 & 2. Chalina spinifera, n. sp.? 1. Specimen, of natural size. 2. A 

 portion of the same, enlarged 3 diam. to show the surface- 

 reticulation. 



Figs. 3-6. Dictyocylindrus aceratis, n. sp. 3. Specimen, about natural size. 



4. An acerate fibre spicule. 5. An acuate setaceous spicule. 6. A 

 short, spined echinating spicule. The spicules all magnified to the 

 same scale. 



Figs. 7-10. JSIicrociona acerato-obtusa, n. sp., the various kinds of spicules, all 

 magnified to scale. 7. Long skeleton-spicule. 8. Shorter stouter 

 acuates. 9. A tricurvate flesh-spicule. 10. Navicular equianchorate 

 spicules. 



Fig. 11. Axinella virgulfosa, n. sp. Eepresented of natural size. (Compare 

 figs. 6 & 7, Plate YII.) 



Figs. 12-15. Amorpkinopsis excavans, nov. gen. et sp. 12. A small portion of 

 the surface of the sponge, of natural size. 13. A similar piece con- 

 siderably enlarged, showing its star-like character. 14. Two skeletal 

 acerate spicules. 15. An acuate spicule, also magnified to the same 

 scale. 



