Miscellaneous. o37 



in diameter. They cousist of anastomosing tubes, usuallv opening 

 in groups through common oscula {Tamis primordiali^, Hack.), 

 more rarel^y quite astomatous {Aidoplegma primordiale, Hiick.). 

 Varieties Ascetta protor/enes and A. dktyoides. Hack., are represented 

 among the Minorcan specimens. Triradiates regular. 

 Loc. Mahon, Alcanfa, apparently very abundant. 



2. Ascetta dathnis, Hiick. 



Two astomatous Aidoplegnia-stocks of 30-35 millim. in diameter. 

 The loose tissue formed of slender tubes. Triradiates with slender 

 cylindrical rays, sometimes slightly undulated, apices a little tliit-k- 

 oned. Both specimeus belong to the var. mceandrina. 



Loc. Mahon ; previously known from the Adriatic. 



3. Ascettd hlanca. Hack. 



Among the few specimens are some which as single individuals 

 form a spindle-shaped sac with a naked oscuhini [Ol.;/tUhns). One is 

 a monohlastic Nai-dorus-stoclK. with a common osculum, and another 

 possesses several oscula (Solenisciis). 



Loc. Mahon ; previously known only from the Canary Islands. 



4. Ascaltis canariensis. Hack. 



All astomatous polyblastic stocks, often furuished with one or 

 more pseudostomata, leading into vacuities of the canal-system. 

 They belong to the variety Asouris amcifce. Hack. 



Loc. Mahon ; only known from the Canaries. 



5. Asccdtls minoricensis, sp. n. 



" Triradiates and quadriradiates regular (equiangulafce and equi- 

 radiate) and of the same size. Rays 7-10 times as long as thick, 

 slenderly conical. Apical ray of the quadiradiates straight, half as 

 thick as the three facial ones. Colour in alcohol white or brown." 



Loc. Mahon. 



Two specimens are large astomatous Aulopler/ ma-stocks, 40-50 

 millim. in diameter. A third is a monostomatous st.ock with a 

 common proboscidiform aperture. 



Fam. 2. Leucones. 

 6. LeucaUis piumila, Hiick. 



Most of the specimens are large polyblastic stocks with several 

 naked proboscidiform apertures. Some of them attain a diameter 

 of 70 millim., and one is an astomatous stock with a rather narrow 

 gastral cavity. 



It is singidar that Hiickel describes only solitary personae of small 

 size ; the Minorcan specimens are among the largest of calcareous 

 sponges. In the structure of the skeleton they agree exactly with 

 Hiickel's description ; it consists chiefly of nearly regular triradiates, 

 while the gastral surface and those of the cauals are lined with 

 regularly arranged small quadriradiates, the basal ray of which is 

 straight and somewhat longer than the carved lateral ray. 



Loc. Mahon ; previously known trom the Atlantic and Indian 

 Oceans. 



Ann. & Mag. N. Hist. Ser. 5. Vol. xvii. 37 



