410 CALIFORNIA ACADEMY OF SCIENCES [P»oc. 4th See. 



Tonicella lineata (Wood) 

 Mopalia lignosa (Gould) 

 i ciliata (Sowerby) 



Placiphorella velata Carpenter 

 I schno chiton magdalenensis (Hinds) 

 cooperi Carpenter 



Of the 39 specimens taken, about three-fifths are Ischno- 

 chiton magdalenensis, an eighth are Mopalia ciliata, an eighth 

 are I schno chiton cooperi, and a tenth are Tonicella lineata. 



11. Nob Hill Cut, San Pedro, California (Oldroyd). 



I have not been successful in finding a published account of 

 this very interesting exposure, although to judge from the 

 chitons (I have seen no other representatives) it must possess 

 a somewhat remarkable fauna. The chitons attain a consid- 

 erable development here and include the following species: 



Lepidochitona dcnticns (Gould) 

 Nuttallina calif omica (Nuttall) 

 Mopalia muscosa (Gould) 

 acuta (Carpenter) 

 Cryptochiton stclleri (Middendorff) 

 I schno chit on fallax Carpenter 



cooperi Carpenter 

 Callistochitou crassicostatns Pilsbrv 



palnuilatus mirabilis Pilsbry 



Over half of the 117 specimens obtained here by Mr. Old- 

 royd are Lepidochitona dcnticns, nearly one-fifth are Mopalia 

 acuta, and about one-eighth are Callisto chiton crassicostatns. 



12. "Crawfish George's", near Yacht Club, San Pedro, 

 California (Arnold, Chace). 



This exposure has been very comprehensively treated by 

 Arnold ( :03, p. 24-27, 35-47). He records no chitons. Mr. 

 Chace's material, however, includes the following three : 



Mopalia muscosa (Gould) 



" sp. 

 Ischnochiton cooperi Carpenter 



The fauna as listed by Arnold includes a remarkable num- 

 ber of northern types, mingled as well with some of the more 



