PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 93 



without snout. D.8; A. 8; V. 9; scales 14-74-9; teeth 1, 5-5^ 1 ; length 

 11|^ inches. 



While it is certain that the persistent pharyngeal teeth are as stated, 

 I must note that a small tooth was found loose in the tissues covering 

 the dentigerous bones. It may be that this fish had the normal num- 

 ber and two of them were displaced by accident. Four of the teeth of 

 each side are molar-like. 



9. Richardsonius balteatus (Rich.) Grd. 



o0322 (38:!) 9 1 specimen, Garrison Creek, Wash. Ter., .Inly, 1881. 



Length of example 4 inches. Teeth 2, 5-5, 2, hooked, without grind- 

 ing surface. Body compressed, resembling Notemigonns. Snout % as 

 long as eye, 4 in bead. Eye 3 in head. Head ^ of greatest height of 

 body, almost 4i in length to end of scales. Maxilla 3 in head, mandi- 

 ble 2i. -Dorsal behind ventrals, much nearer caudal than end of snout, 

 its base equal to ^ of its distance from snout. Longest dorsal ray equals 

 length of pectoral, 5^ in lengtli to end of scales. Anal basis nearly 

 equals head, 4f in length to end of scales. Ventral nearly equi-distaut 

 from snout and end of scales. D. 10; A. 18; Y. 9;. scales 12-63-S. 



10. Lampetra tridentata (Gairdner) Jor. & Gilb. 



:50295 (347) 1 specimen, Walla Walla R., Wash. Ter., May 6, ISSl. 

 30296 (351) 1 specimen, Garrison Creek, Wash. Ter., May 9, 1881. 



"Lamprey eel." dumber 347 is 19 inches long; number 351 is almost 

 exactly as long. The teeth are as in llichardson's description in Fauna 

 Boreali- Americana; the dorsals, however, are separated simply by a 

 deep emargination ; the base of the first is from one-half to two-thirds 

 as long as that of the second; the second dorsal is higher than the first, 

 and is subcontinuous with the caudal. The length of the space occupied 

 by the giil-openings is contained Sh times in total length, and is a little 

 more than the length of the head from end of snout to first gill-open- 

 ing. Greatest height of body C in distance from snout to first dor.sal. 



I have compared the type of Fctromyzon astori Grd. with Lampetra 

 tridentata and find that they are certainly identical, as already pointed 

 out by Professor Jordan. The types of P. ciliatus and P. Ikndus have 

 the dorsals separated by a space nearly or quite half as long as the 

 first dorsal, but otherwise they have the characters of tridentata. 



11. ?Ammocoetes pliimbea (Ayres). 



3(1321 (383) jnv., 1 specimen. Garrison Creek, Wa.sh. Ter., July, 1881. 



1 am in doubt whether or not this small lamprey, 4f inches long, is 

 the larval form of the above-named species or not. The maxillai-y plate 

 is bicuspid, the cusps well se]xirated; the mandibulary plate has 7 teeth 

 of uniform size. I am unable to determine the structure of the other 

 teeth. The lii)s are fringed. Head 8i in length, equal to space occu- 

 pied by gill-openings. Dorsals subcontinuous. Height of body almost 

 equal to head. Perhaps this is Ammoca'tes eibariusGiravd, and may be 

 distinct from A. plumhea. 



