6 CONTRIBUTIONS TO NORTH AMERICAN ICHTHYOLOGY IV. 
3. B. stOMta* Loclvingtou. 
“ Eleven gill openings on eacli side ; ten teetli in tlie anterior and nine 
in the posterior series. Fifteen inches long.” — [LocMngton.) Coast of 
California ; not rare. 
(Lockingtou, Amer. Nat. Dec. 1878, 793.) 
Oedek C.-HYPEROARTIA. 
[The Lampreys.) 
Nasal duct a blind sac, not penetrating the palate. This order is 
equivalent to the single family Petromyzontidcc. (b-r.zp6a.^ ; apzio<^^ 
comiilete; i. e., entire.) {Fetromyzontidce Gunther, 499-509.) 
Family III.— PETROMYZONTID^. 
{The Lampreys.) 
Body eebshaiied, naked, subcylindrical anteriorly, compressed be- 
hind ; mouth nearly circular, suctorial, armed with horny teeth, which 
arc simi)le or multicusxiid, resting on x)ai)illte; those immediately above 
and those immediately below the oiiening of the cesoiihagus more or 
less sxiecialized ; eyes iireseut ; branchial oxienings seven, arranged in 
a linear series along the sides of the “ chest ”5 nostril on the toxi of the 
head ; liiis iiresent, usually fringed ; dorsal fin more or less deeply di- 
vided by a notch ; the i)OSterior xiart commonly continuous with the anal 
around the tail; intestines with a siiiral valve ; eggs small. 
These animals undergo a metamoriihosis ; the young are usually 
toothless and have the eyes rudimentary. Such forms have, until lately, 
been considered as forming seiiarate genera, which have been termed 
Ammoccetes., Scolccosoma, Chilopteriis, etc. 
Genera 5 or 6 ; si^ecies 15 or 20; found in all waters in temi^erate 
regions. They attach themselves to fishes and feed by scraping oil* the 
flesh Avith their rasp-like teeth. Among our species, four groux^s, ai)- 
parently of generic Amine, may be recognized, but the characters in 
*Tliis species maybe identical -with B. polpirema Grd. from Chili, incorrectly de- 
scribed in Proc. Ac. Nat. Sci. Pbila. 1854, 199, and thus characterized by Pntnam, 
Proc. Lost. Soc. Nat. Hist. 1873, IdO: 
“ Head .about one third of total length, and contained about l-J times in the length of 
the abdomen. Tail contained 7 to 8 times in total length. Base of tongue between the 
seventh or eighth 2 >oir of gills. Gills ten on each side. Length from 13 to 22 inches. 
Habitat : Coast of Chili.” 
