JOURNAL OF ENTOMOLOGY AND ZOOLOGY 229 



The distinctness of the species is confirmed by the radula, which 

 has the teeth in about 58 rows, the formula for 29th row being 

 16-22-2-2-22-16. The inner 2-2 represents the rhachidian plates, 

 which are very different from those of T. carpenteri, the inner 

 ones being strap-like, very greatly transversely elongated, while 

 the outer are also elongated. The form of the pleural teeth and 

 uncini is about as in carpenteri, but the pleural teeth are more 

 numerous. The labial disc is characteristic of the genus. 



The Californian species of Triopha may be separated thus. It is 

 doubtless correct to refer Cooper's Triopa catalina to this genus. 



Body with light spots on a dark ground 1 



Body without light spots 3 



1. Frontal appendages 14; ground color, yellowish; processes 



vermilion. catalina (Cooper). 

 Frontal appendages 12 or fewer; ground color brown, often 

 dark 2 



2. Branchial plumes bright red. macidata McFarland. 

 Branchial plumes white, the tips more or less red. 



grandis McFarland. 



3. Body yellowish brown, processes tipped with vermilion; pleural 



teeth on each side, 7 or 8 In a row. 



grandis McFarland variety. 

 Body orange, processes tipped with vermilion; pleural teeth on 



each side, 4 in a row. aiirantiaca Cockerell. 



Body white, with the processes vermilion; pleural teeth on 



each side, 9 or more in a row 4 



4. Rhinophores red; frontal appendages red. 



carpenteri (Stearns). 

 Rhinophores yellowish olivaceous ; frontal appendages white. 



scrippsiana Cockerell. 



