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



is, here) to feniiginous or brick-red, wliicli, when the specimen 

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

 more striking when it has grown together with Grantia niveaj 

 which retains its w^iite colour throughout. 



So much for the nomenclature and history of this beautiful 

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

 " Glathrinar 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. 



Fig. 1 . Ectycm sparsus, Gray : fragment much magnified, to show : — a aaa^ 

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

 situated on the outside of tlie fibre ; r, fixed ends of the spicules 

 from wliich the rest of the shaft has been broken oft'. Scale 

 l-12th to l-1800th of an inch. 



Fiy. 2. Tlie same, portion of surface, to show the two kinds of oscules, 

 viz. large and small : «, large oscides ; 6, smaller oscules ar- 

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



Fig. 3. The same: a, spicule much magnified; 6, section of the same, 

 near its base. Scale l-12th to l-6000th of an inch. 



Fig. 4. Acanius innoininatus, Gray; diagi'am of fragment of surface, to 

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

 indicating the bundles of acuate spicules -whicli form the 

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

 actual measm'ement \ h b b, capitate spicules projecting into the 

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

 thickened ])y the presence of sarcode densely charged with the 

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

 1-1 800th of an inch. 



Fig. 5. Tlie same, knot or angle of union of the acuate spicules, more 

 magnified : a a a a, acuate or skeleton-spicules 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 ; d dd, tricurvate or bow-like spicules confined to the 

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

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

 l-1800th of aninch. 



Fig. G. 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, 

 recui"ved, sometimes 5-spined (see fig. 5,ff) ; c, small capitate 

 spicule, shaft straight, sparsely spined, .spines recurved ; d, tri- 

 curvate or bow-like spicule ; c, equinnchorate spicule, anterior 

 view; /, lateral view. Scale l-12th to 1-COOOth of an inch. 



