Nov. 3, 1887] 



NATURE 



1832, and in the following year Quoy and Gaimard figured 

 and described Iheir Alcyonelluin speciostim. During the 

 next twenty years only five more species were added to 

 the list, the beautiful Euplectella aspergillutn, Owen, being 

 the most remarkable of these. The last twenty-five 

 years have, however, witnessed an ever-advancing pro- 

 gress in our knowledge of these Sponges, thanks to 

 the labours of Gray, Bowerbank, Wyville Thomson, 

 Schmidt, Kent, Carter, Marshall, Sollas, and, above 

 all, of Zittel, which labours have now culminated in 

 the present Report. 



It is scarcely to be wondered at that the beautiful 

 glassy frame-work and the charmingly diversified spicules 

 which form their " skeletons " have always attracted 

 attention to these Sponges — an attraction that will be 

 greatly intensified by the publication of this volume. 



The Report opens with a general historical introduction, 

 and then passes on to details of the forms and struc- 

 tures to be met with in the group : herein we find the 

 nomenclature adopted for the spicules. This is followed 

 by the description of the genera and species. It is 

 pleasant to find in the synonymy and specific details that 

 great pains have been taken to mention the work of all 

 previous labourers in the field, and the author shows a due 

 and kindly appreciation of what has been done by those 

 who often had but little light to guide them on their way. 



It is not easy to give any analysis of so elaborate a 

 memoir, in which twenty new genera and sixty-five new 

 species are described ; while with scarcely an exception 

 the numerous species already described are not only 

 alluded to, but many fresh details are given about 

 them. When it is recollected that but fourteen years 

 ago only thirty species of this group of Sponges were 

 known, the progress of our knowledge of them, it will be 

 recognized, has been great. 



These Sponges seem to be widely distributed in all the 

 oceans ; the largest number of forms — fifty-seven — being 

 found in the Pacific Ocean ; next comes the Atlantic 

 Ocean, in which twenty-four species were found ; while 

 only sixteen were found in the South Indian Ocean ; but 

 it must not be forgotten that the South Indian Ocean has 

 been very slightly investigated. 



As to the bathymetrical distribution of the Hexactinel- 

 lida, they would appear to be met with in depths of 

 between 95 and 3000 fathoms, being more numerous be- 

 tween the depths of 100 and 900 fathoms, decreasing 

 somewhat between those of 900 and 2500 fathoms, and 

 again markedly diminishing between the depths of 2500 

 and 3000 fathoms, while below this depth no Hexactinel- 

 lida Sponges have been found. Euplectellids seem to 

 have a wide range, being met with at the moderate depth 

 of 95 fathoms, and then being pretty evenly distributed 

 down to a depth of 2750 fathoms. The four species of 

 the new genus Holascus frequent great depths, varying 

 from 1375 to 2650 fathoms. The maximum depth as yet 

 known for any of these Sponges is that of 2900 fathoms, 

 at which depth Bathydortis Jimbriatus was found in the 

 middle of the North Pacific Ocean. 



It would be obviously impossible to give even a brief 

 summary of the very remarkable new forms described in 

 this splendid memoir of Prof. Schulze, and it is difficult to 

 convey a correct notion of the beauty of the illustrations 

 forming the large atlas of plates which accompanies the 



text. The diagnoses of the genera and the descriptions 

 of the species are what one would expect from the well- 

 known skill of the author. 



We do not altogether agree with him when he writes 

 that, " after a detailed investigation of a group of ani- 

 mals, it is incumbent on every naturalist who accepts the 

 evolution theory to attempt the appreciation of his results 

 in their relation to the phylogeny of the group." Look- 

 ing at his array of facts, is it not possible for the thought- 

 ful worker to bear in mind the incompleteness of the 

 phylogenic record, and reverently to wait for more light ? 

 There may be nothing to object to in the stately genea- 

 logical tree of the Hexactinellida represented on p. 495 , 

 but is it not built up on but an incomplete and scanty 

 framework ? 



One departure in this Report from the ordinary custom 

 in the description of species we notice with regret — viz. 

 that there is no synonymic list affixed to the species, 

 neither are we referred, in connection with each form, to 

 the place or places where it has been previously described. 

 It seems scarcely necessary to point out the inconveniences 

 attending such a style, or the great uncertainty it may on 

 occasions give rise to. The volume opens at the descrip- 

 tion of Rosella antarctica, Carter. To find where it was 

 first described by Mr. Carter we are obliged to refer to 

 the synonymy affixed to the diagnosis of the genus ; but 

 here we get no certain information as to how many of the 

 quotations given refer to this species ; and this is of course 

 much more confusing when we come to investigate a 

 genus abounding with species, like, for example, Hyalo- 

 nema. Indeed, by this method an author is very apt to 

 overlook the fact that several writers may refer to the 

 same species under quite different names, and a curious 

 case of this nature, we suspect, occurs under Hyalonema. 

 Dr. Gray, wrongly trusting to a Museum label, replaced 

 the name Hyalonema sieboldii, which he had given to the 

 first known species of this genus in 1835, by that of H. 

 mirabile, under the impression that he had so named it 

 in the " Synopsis of the Contents of the British Museum," 

 1832 (misprinted 1830), the year he had got the analysis 

 of its glassy fibres from Mr. Pearsall. Depending 

 on the accuracy of Dr. Gray, many authors referred to 

 the species under this latter name ; and further, for some 

 time after the discovery of the Setubal species by Prof. 

 Barboza du Bocage, this species, now known as H. lusi- 

 tanicuin, passed as the same species as H. mirabik = H. 

 sieboldii. Even from the details given by Prof. Schulze, 

 this seems clear ; but in the description of Bocage's species 

 (p. 225) no synonymic list is given, and not only does the 

 before-mentioned fact not appear, but we find H. lusitani- 

 cum placed among those species "the upper end of 

 which was not sufficiently preserved for deciding the 

 question whether there is a sieve-plate or not." It is 

 added that " neither on this specimen (the one figured in 

 the Proc. Zool. Soc Lond.) nor on others which Bocage 

 afterwards obtained from the same locality could any 

 portion of the sponge body be detected." But on p. 186 

 we find it stated that H. lusitanicum had been dredged 

 from a depth of 480 fathoms south-west of Setubal, " bear- 

 ing a sponge body with several oscular openings" ; and 

 again on the same page that among the Hyalonema found 

 off the coast of Portugal by Barboza du Bocage and 

 others, and named H. niirabile, there was one specimen 



