2 Mr. H. J. Carter on the Anatomy 



3. A further Division into Subfamilies, Genera, and Species 

 so far as our knowledge extends ; to which will be added a 

 short commentary. 



As regards the First Part, this is almost entirely abridged 

 from my own observations, which have been long since pub- 

 lished in the pages of the ' Annals ' in extenso ; hence my 

 former papers will be constantly referred to, for supplying 

 more extended and more satisfactory information than can be 

 embodied in an introduction. 



The Second and Third Parts rest chiefly on my study and 

 arrangement of the general and private collections at the 

 British Museum, where every specimen has been microscopically 

 examined and the microscopical elements delineated, and will 

 include in addition rough sketches and preliminary descriptions 

 of the most typical and striking specimens, together with the 

 register-number of the specimen and my own private running- 

 number, which has also been attached. This of course has 

 been a work of patience and time rather than one of difficulty ; 

 but it has led to a general acquaintance with the Spongida which 

 could not otherwise have been obtained, at the same time that 

 it has enabled me to make the classification given hereafter, 

 which I found absolutely necessary before I could put the 

 general collection at the British Museum into any kind of 

 order that might be practically useful. 



In my General Arrangement, so far as orders and sub- 

 orders are concerned the way to me was clear ; but I 

 cannot say so much for the families, and still less for the 

 subfamilies, genera, and species, which require a far wider 

 range of specimens in much better condition than those which 

 I have had at my command, although probably the largest 

 and finest collection in the world. Still, from what is here- 

 after stated, it will be seen that we may have to wait so long 

 for the latter that it is desirable to begin with what we possess, 

 correcting the errors as more and better specimens are accumu- 

 lated, since the characters which I have assigned as the limit 

 to a group to-day appear to be often upset by a new specimen 

 examined on the morrow ; hence the late Dr. Gray was wont 

 to observe respecting the Spongida, that " an accurately illus- 

 trated description of a species is the best contribution that can 

 be made to the subject in its present state." 



Our knowledge of the Spongida is altogether in its infancy ; 

 and hence I have called my observations " Notes," viewing 

 them only as preparatory to what hereafter may become 

 entitled to a more comprehensive term — at the same time 

 seeing that it is necessary to make a beginning ! 



Again, as regards arrangement, I have availed myself, 



