CALCAREOUS SPONGES. 775 



90. L. PANicEA Esper. 



iSpongia panicea Esper, ^icZe Haeckel [1872]. 

 Esper's original reference to this species has not been 

 found by us, but Haeckel [1872] states that the species is 

 possibly identical with Leucandra aspiera. 



Genus 36. Baeria Michlucho-Maclay [1870] (emend.). 



Diagnosis. Canal system leuconoid. Skeleton of the chamber 

 layer composed almost exclusively of irregularly scattered 

 colossal quadrii-adia-tes. Mici'oxea pi'esent in large numbers, 

 and of very characteristic form, being almost always pierced 

 with a small hole towards one end. 



For illustrations of this genus see Haeckel [1872]. 



The very characteristic " needle- eye " spicules of this genus are 

 really triradiates, in which two of the rays are very much reduced 

 and have come to lie approximately side by side, being actually 

 fused at their distal ends. In this way we get a linear spicule 

 very slightly swollen at one end, and in the centre of the swelling 

 a small hole, the remnant of the space between the two originally 

 separate rays. That this is the true explanation of these spicules 

 was made abundantly clear from an examination by one of us 

 (Row) of a microscopical preparation of the species preserved at 

 Jena, for while most of the spicules were found to correspond 

 exactly to the type described above, a few of them had the 

 reduced rays not fused together but widely open, thus maintaining 

 the triradiate condition. Exactly similar spicules occur in 

 Kuarrhaphis cretacea (q. v.). 



It may perhaps be pointed out here that these spicules indicate 

 a possible way in which all the calcai'eous monaxon spicules may 

 have originated. At any rate their occurrence adds probability 

 to the presumption that all calcareous oxea have been derived 

 from triradiates in some way or other. 



The only known species of the genus is : — 



1 . B. ocHOTENSis Michlucho-Maclay. 



Baeria ochotensis Michlucho-Maclay [1870]. 

 Leucandy^a ochotensis Haeckel [1872]. 



Genus 37. Leucopsila nov. 



Diagnosis. Canal system leuconoid. Skeleton of the chamber 

 layer composed almost exclusively of irregularly scattered 

 colossal quadriradiates. Gastral cortex well developed, but 

 without any radiate spicules, the whole of the gastral skeleton 

 being formed of a dense layer of microxea. 



