8fi8 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY - IV. 



Page 7. The genus 4 (a) Entosphenus should probably be admitted, 

 and its species should be 

 4. E. tridciitatus (Gairduer) Gill. 



It ranges from Monterey to Vancouver's Island, and Nos. "5" and 

 "6" are not distinct from it. 



On page 8, after Ammoccetes pliinibeus, add: 

 7 (&). A. aureus Bean. 



Plumbeous above, golden yellow below; under side of head and neck 

 silvery. Maxillary tooth single, bicuspid; mandibulary with 7 cusps, 

 the outer largest. Head shorter than chest; distance from eye to first 

 dorsal thrice base of first dorsal; base of second dorsal twice as long 

 :is that of first, the fin twice as high; interspace between dorsals 

 length of head; tail (from vent) 4 in total length. Head 10 (5 in 

 distance to first dorsal). L. 15 inches. Yukon River, Alaska; abun- 

 dant. (Bean.) 



(Ammocoeics anrcus Bean, Proc. U. S. Nat. Mus. iv, 1881, 159: $ Petromyzon marinus 

 atmtttchaticus Pallas, Zoogr. Rosso-Asiat. iii, 1811.) 



On page 9, after Ammoccetes niger, add: 

 d>). A. appendix (Dekay) Gill. 



Dusky brown, sometimes tinged with bluish; fins pale amber. A 

 rin of irregularly-shaped corneous processes within the mouth, and a 

 large isolated double tooth of the same texture on the inferior portion 

 of the mouth. Origin of dorsal in advance of middle of body (behind 

 middle in A. nigcr). Vent near posterior third of body. Anal papilla 

 ( l - appendix") conspicuous in males in spring. Streams of New York 

 and Southern New England. (Dekay.) Not lately recognized, but ap- 

 parently differing from A. nlgcr in the less posterior dorsal. 



( Pe.lromyzon appendix Dekay, New York Fauna, Fish. l-'42, 381: Ammoccctcs unicolor 

 J>rk:iy. 1. c. :Ki; larva. Of the remaining species dcscrihcd by Dekay, Aminni nh-s, 

 Li- Sucnr, 1. c. 383, seems to !>< tin- larva of Pctromi/:it iimriium, and 7'. Inmot- 

 n Le Sueur MSS. 1. c. 38'2, is prohalily I'l-fromi/zon artjaitcitx.) 



Page 10. Pctromyzon caxtancus has been lately received from Loui- 

 siana, It is considered a valid species by Dr. Bean, as is also (6), 

 y. li'n'H(n, (Grd.) Bean. ]ioth tlicsr s}>ecies have the maxillary tooth 

 fi< iis])id, not bicuspid as in ]'. nr<j<')i1<-tis. 



Page 11. The mandibulary teeth in Pefronii/:i>ii marinus are usually 

 7 in number. The plates of the anterior lingual pair are confluent, and 

 t their serrations as stated in the text. 



