46(j SUMMARY OF CfRRENT RESEARCHES RELATING TO 



stony, haril. coral-like iu form, and of black colour. H. turbo n. sp. 

 ikj ciiiefly characterized by its shape. Sarcocornca n. g. has the 

 same character as Hol-psamma, but has the sarcode more or less 

 transformed into keratine. S. nodosa n. sp. is the sole species 

 described. The genus Dysidea Johnston is emended, and four 

 species described, two of which, D. hirciiiiformis and D. chalini- 

 formis, are new. The former resembles D. fra<jilis, but is coarser 

 in structure. The genus Spnujelia is also emended, and one new 

 species, S. steUadermata, described, with a new species of Carterio- 

 sponnia, C. caliciformis. 



The remaining groups of the Hircinida are then dealt with. The 

 family Liochrotida comprises P.-ammouematous sponges on which 

 there are no conuli, but in which the keratose fibre is strongly 

 developed and more or less cored with foreign microscopic objects. 

 Of new species we have : — Stelospongus flabelUfornm. S. tuhercnlatas 

 (provisional) closely resembling S. levis in the structure of the sandy 

 incrustation, &c., the general form is like that of a knotted Chalina. 

 Geeloivjia vasifonnis nov. gen. et sp. affords an iustance of the 

 replacement of the natural sarcode by the supposed parasite Spongio- 

 phaga communis. Abnormally developed ova were found in situ within 

 it. Dadylia chnliniformis n. sp. is a distinctly digito-chalina-like 

 sponge. D. impar n. sp. is " frosted " white with an incrustation of 

 hyaline grains of quartz. D. pahnaia n. sp. is a flattened variety of 

 D. chaliniformis. The family Hircinida comjirises Psammonematous 

 sponges which are conulated on the surface. Hircinia solida n. sp. is 

 characterized by compactness of structure, prevalence of sandy fibre, 

 soft, fleshy, fibro-reticulated dermis, and dark colour. H. intertexta 

 n. sp. is notable for the presence of a microscopic intertestural fibre 

 filling up the interstices of the skeleton. H. JiaheUopalmnta, H. com- 

 munis, aud H. pulchra complete the list of new species for this genus. 

 The family Bibulina comprises Psammonemata having a solid fibre 

 chiefly uithout core of foreign objects. Two new species are added to 

 this family : — Euspongia anfrachiosa n. sp. reseuib'es the representa- 

 tion of Spiongia cavernosa (Duch. et Mich.) and Hyatt's photograph of 

 S. menndriniformis. Paraspongia laxa n. sp. is distinguished for the 

 scantiness of the fibre and its wide reticulation, together with the 

 black colour of the dermis. 



The paper concludes with a revision of the subdivisions of the 

 Fam. Pseudohircinida. 



Protozoa. 



Immortality of Unicellular Organisms.* — Prof. A. Weismanu 

 gives a summary of his views on this subject, which have given rise 

 to a considerable amount of discussion. He concludes that 



1. The controversy whether it is proper in cases of the fission of 

 Protozoa to pronounce mother and daughter as one and the same 

 individual, or as distinct beings, is purely verbal. It has a deeper 



• Biol. Centralbl., iv. (1885) pp. 577-91 and 650-65. See Journ. of Sci.. vii. 

 (1885 pp. 201-5. 



