222 University of California Publications in Zoology  [Vou. 14 
varieties are known to range north of San Francisco, whereas 154 
occur south of that place. These figures are of less value in deter- 
mining the relationships of the fauna to other West Coast faunas than 
are those derived according to a method used by Sumner e# al. (1911, 
p- 184). Those authors compare the number of ‘‘ predominantly north- 
ward ranging’’ species with the number of southward ranging forms. 
They define ‘‘predominately northward ranging’’ species as one, 
“whose range (in latitude) to the northward on our coast is at least 
twice as great as is its range to the southward.’’ Applying this 
method to our fauna as catalogued gives 77 species as predominantly 
northward ranging; 55 as predominantly southward ranging ; 37 whose 
known ranges are nearly equal to the north and south of San Fran- 
cisco; 14 which are known only from San Francisco, and 11 species 
that cannot properly be classified, since their ranges are imperfectly 
known. This indicates, if the faunas north and south of San Francisco 
are about equally well known, that the local fauna has closer affinities 
with the northern fauna than with that to the south. 
Two new species of mollusks have been discovered as a result of 
the dredging operations of the “‘Albatross.’’ They have been de- 
seribed by Dr. Bartsch under the names of Odostoma franciscana and 
Turbonilla franciscanda. 
The molluscan fauna of this region includes several exotic species, 
most of which have inadvertently been introduced with young oysters 
TABLE 3 
ReEcoRD or THE Most Propuctive Bay Station (D 5796) 
No. of 
living No. of 
specimens shells 
(Cada COT DS eeeeeeee eee ee 17 18 
Columbella gausapata -.............--.------------- 0 5 
Miya ceili ommic ay messes 0 10 
Macoma inquimata <-...-.-.-.c:.c2s:-ccceseeeeeeeseee = 0 5 
INTE VEO TATE, TNAVSWHIE), sctsccce secs ececeescceavcoceceseeaneene 0 3 
Monia macroschisma ......-.-------------0<--<------ 0 1 
INDE AerUnUES)) GYCN DING) Seer eee see meee otceeeeereoetee 0 1 
Niassa fossartay 1.202 Seis eee ee et 0 1 
INialsSaimmen ical acest ocee eee eee 0 2 
Ostrea lr day eee eee eens eee ees 0 10 
(Pano bial s balmine a) eee eee ene 0 1 
Schizothaerus nuttalli -......-.---.--------- 0 2 
RSWUUATCG WEE, TAUDH RAN a eet cee cereeenecore score 3 1 
MBCeVi nb aiesye SEW bo dW oy 0 SY: Ve eee ee etceer en gececemecaee seo cen 0 2 
WINE HIS) MEWS), ebereeteascecccencentenentrenne secon il 27 
ZANTE 21m ODD Lae eee tema eee 0 il 
