SUPPLEMENTARY NOTES AND OBSERVATIONS. 389 



" The folio vving five new species, described by us, have also been des- 



"cribed by Hall." 



" IllcEnus worthenanus, W. and M. (/. insignis, Hall)." 



" Acidaspis ida, W. and M. (j1. danai. Hall)." 



'' Clidopkorus mac chesney anus , W. and M. (Modiolopsis rectus, Hall)." 



'^ Bellerophon (Bucania) perforatus, W. and M. {Tremanotus alpheus, Hall)." 



*' Gomphoceras marcycB. W . and M. (Gorriphoceras scrinum, Hall." 



It would seem, from this arrangement, that Prof. Winchell regards 

 the species of W. and M. as having precedence, notwithstanding my 

 species were published a year previous to these. 



The specimens communicated by Prof. AVinchell under the name 

 of lllcenus worthenanus are, the glabella? oi lllcBnus a^inatus ; and one part 

 of a glabella of Ceraurus with hypostoma attached, which is probably the 

 hypostoma described on page 105 of the memoir. The pygidium accom- 

 panying these, under the same name, is apparently the one described on 

 p. 105, and belongs to /. armatvs. In the collections of Prof. Marcy there 

 are several glabellas and imperfect heads of /. armatus^ and a very good 

 head of lllcenus insignis ; all of which were communicated under the name 

 7. worthenanus. 



Acidaspis ida, W. and M., is identical with A. danai,* Hall. Clido- 

 phorus macchesneyanus, W. and M., is Modiolopsis rectus, Hall. I can- 

 not understand why such a form, with distinctly defined muscular impres- 

 sions and absence of anything like a clavicular ridge, should have been 

 referred to CLiDOrnoRUS. 



Bellerophon [Bucania) perforatus, W. and M., is Tremanotus alpheus. 

 Hall, already cited. 



Gompho:-eras marcyce, W. andM., is Gomphoceras scrinium,*' Hall. 



Avicnla undata, Hall. In continuing this reference, I did not of course 

 regard it as a true Avicula, but as having characters so nearly those of 

 that genus, that this reference seemed more proper than any other. The 

 species is not a Pterinea. It has one small anterior tooth in each valve ; 

 and an oblique posterior tooth, with a second shorter one in the right valve. 

 The muscular scar is large and subcentral. These characters appear to me 

 more nearly those of Avicula than of Pterinea. The teeth are correctly 

 described by Prof. Winchell as " posterior, linear, diverging teeth," 

 which are quite oblique at the posterior extremity. The figure, however, 

 gives the teeth as parallel. 



The species referred by me to Modiolopsis subalatus ? is not a Pterinea : 

 neither do the specimens thus referred by Prof. Winchell "possess the 

 characters of a true Pterinea;" nor do I see any objection to its refe- 



• Prof. Winchell having expressed a desire to retain the names of Acidaspis ida and 

 Gomphoceras marcyce for the species published as above by me, I am quite willing to 

 relinquish the claim of priority so far as I am personally concerned, and shall be gratified 

 to sec these names adopted by naturalists. 



