IN THE MOEPHOLOGT OP THE CYSTIBEA. 47 



system of the genital segments consists almost entirely of a 

 complex system of tubes, whicli ramify in the thickaess of the 

 body-wall, which open by numerous pores on to the exterior, and 

 are connected by a few short tubes with the body-cavity." Witli 

 a little modification this description would be fairly applicable 

 to the water-vascular system o£ an T^chiuoderm ; and Field's ob- 

 servations show that there is much to be said, for Hartog's 

 conclusion *, that " the madreporic system of Echinodermata is 

 morphologically and ontogeuetically a (left) nephridium." 



3. The Oscular Orifice. 

 Before I had finished correcting the proofs of the preceding 

 pages I received, through the kindness of Mr. E. A. Blair, of 

 Sedalia, Missouri, an advance copy of the Palseontology from the 

 Seventeenth Report of the Geological Survey of Indiana. It is 

 from the pen of that ardent species-maker Mr. S. A. Miller, who 

 adds fifteen more to the nineteen species of Holocystis which lie 

 has already described from tlie Niagara group of Indiana, while 

 Hall, the founder of the genus, described another half-dozen from 

 "Wisconsin. Like the reviewer of Barrande's " Cystids " in 

 ' Nature,' I would emphatically protest against the continued 

 use of the termination ites for most generic names of Cystidea. 

 No modern palseontologist, not even S. A. Miller, who is an 

 ultra-conservative in all matters of nomenclature, now writes 

 Cyatliocrinites, Foteriocrinites^ or Rliodocrinites, as did. their 

 famous author, J. S. Miller, in 1821. Why, then, do our palaeon- 

 tological works contain such lengthy names as AmygdalocystUes, 

 Anomalocystites, and. Strohilocystites ? The editors of Angelin's 

 ' Icouographia ' wrote Caryocystis, I^ucystis, Glyptocystis, Gom- 

 plwcystis, and. Ilegacystis in 1878, with the remark, " Nominum 

 genericorum exitus in ites, regno lapideo principle proprius, regno 

 animali alienus ;" but their example has not been followed to any 

 great extent. The change involves a feminine termination to 

 the specific names, and also renders a new generic name necessary, 

 for the name Solocystis was given by Lonsdale in 1849 to a well- 

 known Cretaceous coral, and Holocystites, Hall, only dates from 

 1861. Hall himself drew attention to this fact somewhat laterf 



* " The True Nature of the ' Madrepoi'ic System ' of Echiuodermata, with 

 Eemarts on Nephridia," Ann. Mag. Nat. Hist. ser. 5, vol. xx. 1887, p. 325. 



t " Twentieth Annual Report, New York State Cab. Nat. Hist.," Albany, 

 1867, p. 380. 



