POEIFEEA. 



III-CALCAEEA. 



By C. F. Jenkin, B.A. 



(12 Plates.) 



PAET I. 



Introduction and Classification. 



INTRODUCTION. 



The preparation of the Report on the 'Discovery' collection of calcareous sponges 

 was, in the first instance, entrusted to Professor E. A. Minchin. He had partially 

 examined the Homocoela and made some drawings of them, when he was unfortunately 

 obliged to abandon the undertaking, owing to the pressure of other duties. The 

 collection was then entrusted to the author, who has had the advantage of using 

 Professor Minchin's notes on the Homocoela and his lifelike drawings (Figs. 12 and 14), 

 showing the habit of growth of the two new species of Leucosolenia. 



The author desires to record his indebtedness to Professor Minchin for much 

 valuable advice, to Professor Dendy for valuable suggestions as to the classification of 

 the new genera, and for specimens of Grantiopsis cylindrica, to Mr. R. Earkpatrick 

 for constant help and particularly for permission to examine the British Museum 

 collection of calcareous sponges, to Professor R. von Lendenfeld for specimens of 

 Sycon tenellum, and to Professor Jeffrey Bell, to whose kindness he owes the privilege 

 of undertaking this most interesting investigation. 



The collection consists of 109 specimens. Of these, 39 belong to the grade 

 Homocoela, and are divided among five species, of which two are new to science. The 

 remaining 70 belong to the grade Heterocoela, and are divided among 18 species 

 and one variety of an existing species, all of which are new to science.* 



Of the five species belonging to the grade Homocoela, two belong to the genus 

 Clathrina and three to the genus Leucosolenia. 



Of the 18 new species of Heterocoela, five belong to the genus Leucandra and the 

 remaining 13 are distributed among six new genera. 



CLASSIFICATION. 



The classification here used, which is shown in the following table, is that 

 proposed by Polejaeff" (4) for the Homocoela and by Dendy (2) for the Heterocoela 



* With the possible exception of three of the species, which can only be considered as provisionally settled. 



2 H 2 



