1887.] NATURAL SCIENCES OF PHILADELPHIA. 261 



expanded and prolonged into a tube of variable length in the differ- 

 ent species, whose termination is either fimnel-shaped, disk-like with 

 fibrous margins, or divided into one or several cirrous appendages 

 •sometimes of considerable relative length, curling or tAvisting about 

 each other or surrounding objects. Birotulate spicules akin to those 

 of Meyenia or Hetromeyenia. (PI. VI, figs, iii, iv, v and vi.) 



The name Carterella was first applied to this genus in June 1881, 

 at the suggestion of Mr. (now Prof) Jno. A. Ryder, in honor of my 

 friend H. J. Carter, Esq. F. R. S. etc. whose scientific life, more 

 than that of any other man had been devoted to the study of the 

 marine and fresh water sponges. During the previous summer two 

 species possessing the features indicated had been discovered by 

 Mr. Mills of Buffalo and myself, and briefly described as of the genus 

 Spongilla, which had not then been divided. The approval of Mr. 

 Mills was courteously given to the use of the name Carterella, which, 

 a few years later was necessarily changed to Carterius, on the dis- 

 covery that the former term had been preoccupied by Zittel in the 

 same association, to designate one of his fossil types. At that time 

 and for several years after, the occurrence of cirrous appendages was 

 altogether unknown among European sponges; but the past few 

 years, which have been so fruitful of American species in foreign 

 parts, have developed one of this type in Russia, and later, in Bohe- 

 mia, called by its discoverer, Dr. W. Dybowski, Dosilia stepanowii. 



The tendrils of the three recognized American species, C. tubisper- 

 ma, C. latitenta and C. tenosperma, differ obviously in length and 

 character, and with the Russian species probably present as many 

 types of these organic features, as it will be profitable to designate 

 by specific names. Several intermediate forms have, however, been 

 noticed by Mr. Mills and B. W. Thomas Esq., of Chicago, varying 

 as to the length of the foraminal tubules and the character of the 

 supported tendrils ; the most noticeable case, being the substitution 

 of a flaring funnel-shaped termination of the tubule, for the latter 

 organs. 



KEY TO THE SPECIES OF THE GENUS CARTEKIUS. 



1. Foraminal tubule terminating in a sub-quadrangular disk at 

 whose angles the chitin divides into processes of variable length. 

 (PI. VI, fig- iv.) C. (Dosilia) stepanowii. 



2. Foraminal tubule very long and slender; tendrils short, irregu- 

 lar, or wavering. (PI. VI, fig. iii.) C. tubisperma. 



