Vol. VII] BERRY— WEST AMERICAN CHITONS 235 



7. Schizoplax brandtii (Middendorff) 



Taken at Forrester Island, and at the Waterfall Cannery, 

 Prince of Wales Island. Schizoplax was found only on 

 shore, and there "under rocks at pretty low tides." 



The largest specimen seen measures as follows : 



Maximum length of animal 18 mm. 



Maximum width of animal 13.5 mm. 



Length of shell alone 17.5 mm. 



Width of fourth valve inside girdle 13 mm. 



8. Ischnochiton interstinctus (Gould) 



Dredged in 10 fathoms in Sitka Harbor in 1913. and in 

 10 to 20 fathoms at Forrester Island in the three subsequent 

 years. This and /. mcrtensii are by far the most abundant 

 of the dredged species. It was not taken between tides. 



9. Ischnochiton radians Carpenter 



Specimens which seem unmistakably to belong to this 

 species were taken on shore at the Waterfall Cannery, Prince 

 of Wales Island, and near Cape Lookout, Dall Island. So 

 far as I have been able to ascertain, they constitute the first 

 Alaskan record for the species. Barkley Sound, B. C, was 

 previously the most northern station recorded. 



7. radians and 7. interstinctus are very closely related and 

 though most lots may be readily separated by their relative 

 size and color, some of the specimens are sufficiently inter- 

 mediate so that with occasional undissected shells I have 

 had to fall back upon the blue-green interior usually pos- 

 sessed by radians and similar trifling features to separate 

 them. 



Three of the four specimens taken at Dall Island [S. S. B. 

 258] are of a peculiar dark color variant which is also found 

 occasionally in the vicinity of Monterey. 



10. Ischnochiton (Lepidozona) retiporosus Carpenter 



Taken at Forrester Island in 15 to 50 fathoms. While 

 dredged occasionally in 15-20 fathoms in association with 



