88 THE VOYAGE OF H.M.S. CHALLENGER. 



condition. It seems just possible, therefore, that, as originally suggested by Sars ^ in 

 the case of the first known species of the genus, Cladorhiza abyssitola, these sponges 

 have some method of obtaining their supplies of nutriment which is quite difi'erent from 

 that found in other sponges ; this is, however, extremely unlikely. 



As regards the genus Crinorhiza itself we are necessarily in doul^t. It was founded 

 by Schmidt, and aU that he wi'ote about it is contained in the five lines in which 

 he describes his Crinorhiza araphactis} The description is too short to be of much 

 service for identification, but inasmuch as he mentions and figures an osculum at the 

 summit of the sponge we are quite satisfied that none of our forms are specifically 

 identical with his. The external reseml)lance is however striking, and while the genus 

 Crinorhiza will probably have to be abolished, we gladly make use of the name for 

 that particular external form. In this course we are supported by the example in 

 cognate circumstances of Haeckel in the case of the Calcarea, and of Smitt and 

 Hincks in that of the Polyzoa. Indeed, the existence of well-marked external forms 

 running through difi'erent genera has already been thoroughly recognised in Haeckel's 

 classical work Die Kalkschwamme, and lies at the foundation of the new departure 

 in Polyzoan classification taken by the authors we have named. 



Crinorhiza forms also occur in the closely allied genus Chondrocladia, Wj."v. 

 Thomson, and in the still more closely allied genus Axoniderma, nobis, but to these cases 

 we shall recur later on. They certainly have a very wide geographical range, for 

 the Challenger brought home species of Cladorhiza, having this form from the North 

 Pacific (2385 fathoms ; bottom, red clay); the South Pacific (3000 fathoms ; bottom, 

 red clay); and the South Atlantic (2200 fathoms ; bottom, Globigerina ooze); as will 

 be found fully recorded under the various species. 



The geographical distribution of the genus is now known to be very wide, and includes 

 the North and South Atlantic, the Southern Ocean and the North and South Pacific. 



The Cladorhiza are essentially deep-sea sponges, and are not unfi-equently 

 obtained at depths of between 2000 and 3000 fathoms, and they afford some of the 

 most striking examples known of the symmetry and beauty which characterise 

 Monaxonida living in very deep water. 



Cladorhiza ahyssicola, Sars, var. rectangular is, nov. (PI. XX. fig. 10). 



1872. Cladorhiza ahyssicola, Sars, Remarkable Forms of Animal Life from the great deeps off 



the Norwegian Coast, pt. i. p. 65. 



Sponge (PI. XX. fig. 10) consisting of a straight, slender, cylindrical stem, 



unbranched ; terminating above in a rounded extremity and below in several delicate, 



forking rootlets. Length of stem 50 mm.; diameter 1 mm.; greatest length of roots 



25 mm. All the way up the stem, coming off at right angles, from four sides, arise 



1 Remarkable Forms of Animal Life, pt. i. p. 68. ^ Spong. Meerb. von Mexico, pt. ii. p. 83. 



