Classification of the Asconidse. 359 



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

 as has been observed : — 

 Larva a parenchyniella. First spicules to appear triradiate systems. 



1. Clathrina clathrus (type species). 



Grantia clathrus, Schmidt, 18G4. 



2. ClatJirina coriacea. 



Spongia coriacea, Montagu, 1812. 



?>. Udhrina lacunosa. 



Grantia lacunosa, Johnston, 1842. 

 Syn. : Ascandra angidata, Lendenfeld, 189], 



4. Clathrina reticulum. 



Nardoa retictdum, Schmidt, 1862. 



5. Clathrina contorta. 



Leuco&olenia contorta, Bowerbank, 1866. 



6. Clathrina hlanca. 



Gtiancha hlanca, Miklucho-Maclay, 1868. 



7. Clathrina primordialis. 



Ascetta primordialis, Hackel, 1872. 



8. Clathrina cerebrum. 



Ascaltis cerebrum, Hackel, 1872. 



9. Clathrina spinosa. 



Ascetta spinosa, Lendenfeld, 1891. 



II. 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). 



Spongia hotryoides, Ellis and Solander, 1786. 

 Syn. : Ascandra botrys, Hackel, 1872. 

 ? Ascandra nitida, Hiickel, 1872. 



2. Leucosolenia complicata. 



Spongia complicata, Montagu, 1812. 

 Syn.: Ascandra pinus, Hackel, 1872. 



3. Leucosolenia Lieherkuhnii. 



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 ' Munograph of the British Spongiadas ' (Ray Society, 

 1874). They are simply specimens of Leticosulenia vuriabiUs iu which 

 the monaxons attain a great development, and their label bears on it, iu 



