Classification of the Asconidae. 359 



To these diagnostic points we may add, as constant characters, so far 

 as has been observed : — 

 Larva a parenchymella. First spicules to appear triradiate systems. 



1. Clathrina clathrus (type species). 



Grantia clathms, Schmidt, 1864. 



2. Clathrina coriacea. 



Sjjongia coriacea, Montagu, 1812. 



3. hdhrina Jacunosa. 



Grantia lacunosa, Johnston, 1842. 

 Syn. : Ascandra angvlata, Lendenfeld, 1891. 



4. Clathrina reticulum. 



Nardoa retictdum, Schmidt, 1862. 



6. Clathrina contorta. 



Leticosolenia contorta, Bowerbank, 18(36. 



6. Clathrina hlanca, 



Guancha hlanca, Miklucho-Maclay, 1868. 



7. Clathrina primordialis. 



Ascetta primordialis, Hackel, 1872. 



8. Clathrina cerebntm. 



Ascaltis cerebrum, Hackel, 1872. 



9. Clathrina spinosa. 



Ascetta spinosa, Lendenfeld, 1891. 



11. Genus Leucosolenia, Bowerbank, 1864. 



The adult colony has the form of a cluster of relatively large erect 

 oscular tubes, which send out numerous diverticula and are often arbo- 

 rescent, united typically by a more or less stolon-like system of finer tubes, 

 Triradiate systems always sagittal. Collar-cells with nucleus at apex, 

 close under the collar. 

 To this may be added, as probably constant characters : — 

 Larva an amphiblastula. First spicules to appear monaxons. 



1. Leucosolenia hotryoides (type species). 



Sponffia hotryoides, EUis and Solander, 1786. 

 Syn. : Ascandra botrys, Hackel, 1872. 

 ? Ascandra nitida, Hackel, 1872. 



2. Leucosolenia complicata. 



Spongia complicata, Montagu, 1812. 

 Syn.: Ascandra pinus, Hackel, 1872. 



3. Leucosolenia Lieberkiihnii. 



Grantia Lieberkiihnii, Schmidt, 1862. 



4. Leucosolenia variabilis. 



Ascandra variabilis, Hackel, 1872. 

 Syn. : Leuconia Somesii, Bowerbank, 1874 *. 



* I have been able to examine in the British Museum the three speci- 

 mens of " Leuconia Somesii" figured by Bowerbank on plate xci. figs. 6-8 

 of vol. iii. of his ' Monograph of the British Spongiadse ' (Ray Society, 

 1874). They are simply specimens of Leucosolenia variabilis iu which 

 the monaxone attain a great development, and their label bears on it, in 



