258 PROCEEDINGS OF THE ACADEMY OF [1898. 



DESCRIPTION OF PLATES. 

 Plate IX. 



Figs. 1, 2. Hemphillia glandulosa Bid. & Binn. Dorsal outline 

 and lateral aspect of a specimen from Astoria, Oregon (Hemp- 

 hill, coll.), Mus. no. 71,161. m, mantle; sh, exposed surface of 

 shell. 



Figs. 3, 4. Hemphillia camelus Pils. & Van. Lateral and dorsal 

 aspects of the type specimen. Old Mission, Idaho. Mus. no. 

 63,926. 



Figs. 5, 6. Hesperarion niger (J. G. Coop.). Ventral and lateral 

 aspects of a maculated individual. Santa Clara, Cal. Mus. 

 no. 71,198. 



Figs. 7, 8. Prophysaon cceruleum Ckll. Dorsal and lateral aspects 

 of a specimen which has lost its tail by self-amputation. Olyru- 

 pia, Washington. Mus. no. 63,913. 



Figs. 9, 10, 11. Prophysaon cceruleum Ckll. Lateral, anterior and 

 dorsal aspects of the self-amputated tail of a specimen from 

 Seattle, Washington. No. 71,074. 



Figs. 12, 13, 14. Anadenulus Cockerelli (Hemph.). Ventral, lat- 

 eial and dorsal aspects of one of the original specimens, from 

 Julian City, San Diego Co., California. Mus. no. 63,895. 



Plate X. 



Figs. 15, 16. Prophysaon foliolatus (Gld.). Lateral and dorsal 



views of a typical specimen from Seattle, Washington. Mus. 



no. 71,072. 

 Fig. 17. Prophysaon foliolatus (Gld.) Same specimen, the mantle 



turned backward to show position of its anterior insertion. 

 Figs. 18, 19. Prophysaon Andersoni (J. G. Coop.). Oakland, 



California. Mus. no. 69,010a. 

 Figs. 20, 21, 22. Propthysaon Andersoni (J. G. Coop.), San Juan 



Island, Washington. Mus. no. 63,912. 

 Figs. 23, 24. Prophysaon fasciatum Ckll. Seattle, Washington. 



Collected in March or April, 1896. Mus. no. 68,025. 

 Figs. 25, 26. Prophysaon fasciatum Ckll. Lateral views of two 



individuals from Seattle, Washington. 

 Fig. 27. Prophysaon fasciatum Ckll. Same individual as fig. 26, 



with mantle turned backward to show position of its anterior 



insertion. 



Plate XL 



[All figures represent the digestive tract viewed from above. A. gl., 

 albumen gland; B. d., bile duct; P.m., buccal mass; 6r 1-t , 

 first, second, third and fourth folds of the gut; Gen. or., exter- 

 nal genital orifice ; L, liver ; o. t., ovo-testis ; sp., spermatheca ; 

 T, tail ; ut., uterus ; vag. vagina.] 



