192 
THIRD REPORT on the PORIFERA of the 
Tip WE. (Ce IBIS MMs C0", 
By RicHarp Hanitscu, Pu.D., 
DEMONSTRATOR OF ZOOLOGY IN UNIVERSITY COLLEGE, LIVERPOOL. 
With Plates X.—XV. 
[Read 9th May, 1890.] 
In the two previous reports* on the Porifera of the district 
forty-four species were recorded, one of which was new to 
British seas and three new to science. Several cruises in 
Liverpool Bay during the summer of 1889 and the present 
spring, and also shore-working at the Biological Station, 
Puffin Island, in April, 1889, and at Port Erin, Isle of 
Man, last April, enable me to add twelve species to 
the record, three of which are new to science, making in 
all fifty-six species. 
In my former report I fell into a serious error in regard 
to the structure and systematic position of Sezriola compacta, 
n. sp., and I desire to acknowledge my indebtedness to 
Professor Sollas, D. Sc., for the great kindness with which 
he has pointed out the mistake to me and has answered 
many questions having a bearing on that species. I give 
now a re-description of Seiriola compacta (see below). 
The following table gives all sponges found up to the 
present date in the district, and shows the distribution of 
the species in the four parts in which they have been most 
* « Report on the Porifera of the L.M.B.C. District.” by Thomas Higgin, 
¥.L.S., in ‘‘ Fauna of Liverpool Bay,” Vol. I., 1886. And ‘‘ Second Report on 
the Porifera of the L.M.B,C. District,” by R. Hanitsch, in Proce. Biol. Soe., 
Liverpool,” Vol. III., 1889, and ‘‘ Fauna,” Vol. II. 
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