282 Mr. H. J. Carter on the Nomenclature o/" Clathrina. 



is, here) to ferruginous or brick-reel, which, when the specimen 

 is dried, turns again to yellowish brown. And this is the 

 more striking when it has grown together with Grantia nivea^ 

 which retains its white colour throughout. 



So much for the nomenclature and history of this beautiful 

 calcisponge, finally, I hope, and most appropriately, called 

 " Clathrina.'''' May its synonyms rest here ; for so evidently 

 self-strangling must this course, if continued, be in the end 

 to natural history, that, on naming an object, one may be 

 pardoned for recalling to mind the following lines in Shak- 

 speare's epitaph : — 



" Blest be the man that spares these stones, 

 And cursed be he that moves my bones." 



Then, again, we are not all Shakspeares. 



EXPLANATION OF PLATE XVII. 



Fi(i. \. Ecfi/on sparsiis, Gray : fragment much magnified, to show : — a a a a, 

 horny fibre ; a' a' a', portion of the same, deeper ; b, spicules 

 situated on the outside of the fibre ; e, fixed ends of the spicules 

 from which the rest of the shaft has been broken off. Scale 

 l-12th to l-180Uth of an inch. 



Fif/. 2. The same, portion of surface, to show the two kinds of oscules, 

 viz. large and small : a, large oscules ; b, smaller oscules ar- 

 ranged more or less in a petaloid manner. Natural size. 



Fiff. 3. The same : a, spicule much magnified ; fi, section of the same, 

 near its base. Scale l-12th to l-OOOOth of an inch. 



Fiff. 4. Acarnus iniiominafus, Gray; diagram of fragment of surface, to 

 show its irregular hexagonal structure : a a a, straight lines 

 indicating the bundles of acuate spicules which form the 

 polyhedral structure of the skeleton; a, central heptagon, from 

 actual measurement ; b b b, capitate spicules projecting into the 

 interstices ; c c, knots or angles of union of the acuate spicules 

 thickened by the presence of sarcode densely charged with the 

 anchorate and other spicules figured hereafter. Scale l-48th to 

 ] -1800th of an inch. 



Fiff. 5. The same, knot or angle of union of the acuate spicules, more 

 magnified : a an a, acuate or skeleton-spicnles forming the hepta- 

 hedral structure ; b b b b, large capitate spicules projecting into 

 the interstices; c c c, small spined ones, also projecting into the 

 interstices ; dcid, tricurvate or bow-like spicules confined to the 

 sarcode of the knots ; e e c, equianchorate spicules, with which 

 the sarcode of the knots is densely charged. Scale l-12th to 

 1 -1800th of an inch. 



Fiff. 6. The same, specimen of each of the spicules, still more magnified : 

 a, acuate or skeleton-spicule, smooth, slightly curved ; b, large 

 capitate spicule, smooth, straight shaft, with head 4-spined, 

 recurved, sometimes 5-spined (see fig. 5,ff) ; c, small capitate 

 spicule, shaf+ ctrr^^g^it, sparsely spined, spines recurved ; d, tri- 

 cin-vate or bow-like spicule ; e, equianchorate spicule, anterior 

 view; f, lateral view. Scale l-12th to 1-GOOOth of an inch. 



