Hyatt.] 360 [June 7, 



In relation to the preparation of a catalogue of local 

 plants, Dr. J. C. White suggested the desirability of prepar- 

 ing exhaustive lists of the plants of the richer localities, 

 before these shall become picked out or otherwise changed. 



June 7, 1876. 



The President, Mr. T. T. Bouve, in the chair. Eighteen 

 persons present. 



Dr. W. K. Brooks gave a general sketch of the anatomy of 

 the Tunicata, and showed how Salpa, with its separated 

 sexes and other peculiarities, might be produced on the the- 

 ory of Natural Selection. Dr. Brooks called especial atten- 

 tion to the locomotive powers of Botryllus, a hitherto 

 unknown fact. 



A paper on the Geology of Eastern Massachusetts, by Mr. 

 W. O. Crosby, was presented by title. 



The following paper was read : — 



Genetic Relations of Stephanoceras. By A. Hyatt. 



The group which forms the subject of the present paper was first 

 described by Waagen as part of his genus Stephanoceras, it being 

 with Dactylioceras commune and its allies, united as the "sub-group a" 

 under this name. 1 Cozloceras Pettos was left by the same author 

 under the title of iEgoceras, though the similarities of the latter to 

 Steph. Humphriesianum were fully recognized by Waagen in his sub- 

 sequent paper. 2 In this paper, also, he restricted the use of the 

 name Stephanoceras; and two groups, which had appeared as sub- 

 genera of Stephanoceras in his first paper, were elevated to the rank 

 of full genera, under the names of Kosmoceras and Perisphinctes. 



The preservation of zoological nomenclature in an available form 

 demands above all things that names shall not be uselessly multiplied, 



1 Die Formenreihe d. Amm. subradiatus. Benecke's G-eog. Pal. Beitrage, Vol. 2 

 p. 248. 



2 Ueb. d. Ansatzstelle d. Haftsmuskeln b. Naut. und Amm., Paleontograpbica, 

 Vol. 17, 5, p. 215. 



