"Miscellaneous. 69 



Gumminea3 have branched off between tlio Myxospongiae and the 

 Spongidaj. 



2. In all the forms of this series, from Halisarca to Suherites or 

 Reniera, we meet with the tendency to form flesh-spienles. 



3. The flesh-spicules are quite independent of the rest of the 

 skeleton, and occur in two types, Monactinellan (anchors &c.) and 

 Polyactinellan (stars &c.). 



4. When another skeleton was ah'eady formed by production of 

 fibres, when the flesh-spicules originate they I'emain small and 

 unimportant, and in this case it is of no consequence whether the 

 fibrous skeleton consists of horny substance (Hircinia), connective 

 cords (Gummineoe), or siliceoiis cords (Desmacidonidaj). 



5. When there was no fibrous skeleton when the flesh-spicules 

 were formed they attained considerable dimensions, and on their 

 own part formed connected frameworks. Both the Monactinolbm 

 and the Polyactinellan forms occur in these sponges. The anchor- 

 spicules of the Tetractiiiellidaj perhaps belong in part to the foruicr, 

 and the structures in Totractinellidai andHcxactinellida) originating 

 by reduction of the many rays to 4 or G to the latter group. The 

 Plakinida) unite all these wdth Halisarca. 



From the series of fibrous sponges which culminates in the non- 

 horny ]\[onactinellida3 branches are given off at many points in the 

 same direction, all parallel to that powerful but homologous branch 

 which contains theHcxactinellida) and Tetractinellidsc. — Zoologischer 

 Anzeujer, No. 164, April 7, 1884, vii. p. 201. 



On Orbulina universa. By M. C. Schlumbergee. 



Several naturalists have already paid attention to the genetic 

 relations which appear to exist between the Orhulinoi and the Glohi- 

 geriiue, which are so abundantly distributed in our seas. Pour- 

 talcs* was the first to indicate the presence of a Globir/eriuft in tlio 

 interior of Orbidhue dredged in the Gulf-stream. Dr. A. Krohn t 

 made the same observation upon living Orbulina' taken at JNIadeira. 

 These two observers J concluded that the Orbulina gives origin to a 

 Globigerina, which, increasing in size, finally bursts the sphere 

 which encloses it and escapes to lead an independent existence. 

 Carpenter §, in his classical work on the Foraminifcra, opposes this 

 opinion by a series of irrefutable arguments and retains the two 

 genera Orbulina and Globigerina founded by D'Orbigny. 



Recent researches upon the ombryogeny of the Foraminifcra have 



* Silliman's Journal, J uly 1S58 ; reprinted in this Journal, ser. 3, vol. ii. 

 p. 235. 



t Referred to in a paper by Prof. Max Schultze, in the Arch. f. Naturg. 

 1860, p. 287 ; translated in this Journal, ser. 3, vol. vii. The point is 

 discussed at pp. 311-313. 



\ Krohn simply observed the fact and communicated it to Max 

 Schultze. 



§ Introduction to the Study of Foramiuifera, 1862. 



