Occasional Papers of the Alitscitiii of Zoology ii 



only about two-thirds base of lower lobe; origin of lower lobe 

 as near, or almost as near, anus as atriopore. Preatrioporal 

 length, 3.1 to 3.6 times postatrioporal length. Myotome form- 

 ula : 38 to 40+14 or I5+|9 to 11=62 to 65 (all eight speci- 

 mens counted) ; preatrioporal myotomes more oblique as well 

 as more numerous than those of related species. Gonad 

 pouches 26-25 in one specimen ; 29-27 in another. Maximum 

 length, 5.6 cm. 



II. Branchiosfonia callfornicnsc Andrews 



Branchiostoma, sp. Cooper (1868). 



Branch'wstoma lanceolatuin Jordan and Gilbert (1881; 1883) ; Lock- 

 ington (1882); Jordan (1885); (not of Pallas). 



Branchiostoma elongatmn Eigenmann and Eigenmann (1891; 1892); 

 Eigenmann (1892); (not of Sundevall). 



Branchiostoma californiense Gill, MS.; Andrews (1893); Willey 

 (1894) ; Jordan and Evermann (1895) ; Herdman (1904) ; Lonnberg 

 (1904); Fowler (1907); Starks and Morris (1907); Snyder (1913) ; 

 Hilton (1918). 



Amphioxus californensc Kirkaldy (1895). 



As the synonymy indicates, Andrews rather than Cooper or 

 Gill is the author of this species. 



Diagnosis: — Examination of good series of specimens from 

 Monterey Bay, California, to San Luis Gonzoles Bay, Gulf of 

 California, makes possible the construction of the following 

 diagnosis: Dorsal ray-chambers very numerous, 312 to 374 in 

 five specimens counted (average 337) ; preanal chambers, about 

 50. Higher dorsal chambers five to eight times as high as long 

 in each individual; dorsal fin one-fifth to one-eighth as high as 

 body. Anus located far behind middle of lower lobe of caudal 

 fin ; caudal fin variable in degree of expansion before anus ; 

 distance from atriopore to origin of lower caudal lobe contained 

 0.8 to 2.0 times in distance thence to anus. Preatrioporal 

 length, 2.65 to 3.3 times the postatrioporal length. Myotome 

 formula: 43 to 48+16 to 19+8 to 10=68 to 74 (counts made 

 from twenty-two well-preserved specimens; the count given 



