INVEKTEBRATA, CRYPTOGAMIA, MICROSCOPY, ETC. 277 



Sometimes yellow granules occur both iu the fibrillfe aud in the 

 spongiolin fibres. These are probably ferruginous ; in a decomposing 

 sponge, smelling strongly of sulphuretted hydrogen, they were ob- 

 served to be of a dark blue-black colour. 



Schulze considers it very improbable that the fibrillaD are really 

 part of the sponge ; although he thinks that their parasitic, and espe- 

 cially their algoid nature is by no means proved. 



The dark red-brown colour of many varieties of this species is 

 due to a great accumulation of jiarasitic algae in the cortical layer, as 

 deep as 2 mm. from the surface. 



2. Three other species of Hircinia are described : H. spinulosa, H. 

 foetida, and H. muscarum, all three of which have been referred to the 

 genera Sarcotragiis and Filifera. H. spinulosa is shown to be monoecious. 



3. Oliijoceras coUectrix, nov. gen. and uov. sp. — This new form is 

 remarkable for the great mass of foreign bodies (bivalve shells, bits of 

 coral, &c.) which cover its surface and penetrate into its substance. 

 The superficial layer of the sponge is of a deep black hue, the interior 

 white. The horny skeleton is almost obsolete, consisting of branched 

 and occasionally anastomosing roundish fibres, including an immense 

 number of foreign bodies, such as sand-grains, siliceous spicules, &c. 

 Notwithstanding this great peculiarity in the skeleton, Schulze con- 

 siders Oligoceras to be a near ally of dacospongia. 



Organization and Development of Chalinidse.* — This group, in- 

 teresting as forming a transition between horny and siliceDUS sponges, 

 is studied by Dr. Conrad Keller, of Zurich, who has speeially investi- 

 gated a new species found by him in the Gulf of Naples, and named 

 Chalinula fcrtilis. 



General Features. — The entire sponge may be monozoic, i. e. 

 consist of but one persona, or may assume the form of an irregular 

 mass made up of several persona). In the former case it consists of 

 an upright conical tube, 2-3 cm. long, terminating in an osculuia 

 2-3 mm. in diameter. As to consistency, it is very soft and easily 

 torn, but becomes elastic when dry. 



The horny skeleton consists of a set of principal or radial fibres, 

 radiating regularly outwards from the central gastric cavity, and o{ 

 secondary or cross fibres uniting these. In the lioriiy fibns are 

 embedded siliceous spicules • 01)2-0 '1 mm. long, straight or slightly 

 bent, and pointed or refunded at their ends. 



The colour is yellowisli brown, tlie surface smootli and strewn 

 with pores which are visible to the naked eye, being A mm. in 

 diameter. 



Eduderm. — This layer covers the whole external surface of tlie 

 sponge, and is continuous witli the ondoderm at the margin of 

 the oscula and of the pores.f Li the neighbourhood of tlie oseiila 

 the cells are to bo made out without any previous treatment. In the 

 young state the ectoderm is markedly contractile ; probably the 



* ' Zoitmcli. wias. Z<iol.,' xxxiii. (1870) p. 317. 



t KcIUt'h view of tlio spoii;,'!! ictixlcnii i.s thus aecn to (iillVr fnmi tli;it of 

 Pchiilzc anil Mrt.scliiiikoiV, wtio coiL-^icltr tlic ccllei lining the ciiiials as ectodciiiml, 

 ami only the colLir cells of llie eiliated ehanibcrs as ondodcinial. 



