Our first attempts to identify the abundant spec- 

 imens of Cy clot hone in the survey collections by 

 literature existing at that time were unsatisfactory. 

 A detailed examination was made of this group, 

 and the results and conclusions are summarized be- 

 low. At least, five species of Cyclothone are repre- 

 sented in our collections. 



Some of the specimens of G . signata from the 

 more otfshore localities may represent the tersely 

 described and inadequately know:. C. alba Brauer 

 (B. N. Kobayashi, personal communication). 



The form we designate as Cyclothone sp. (num- 

 ber 33) may be an un described species. There is a 

 possibility that it represents C. pseadopallida, re- 

 cently described by Mukhacheva (1964) (B. N. 

 Kobayashi, personal communication). 



Although Cyclothone microdon (Giinther) has 

 been reported from California waters, none of the 

 specimens taken in the survey can be definitely 

 attributed to this species. C. pallida Brauer has 



also been reported off California, but we find that 

 the form here closely resembles Gilbert's descrip- 

 tion of C. canina ( 1905 :604) ; especially significant 

 is Gilbert's description of the palatine and ptery- 

 goid teeth of C. canina — "palatine teeth confined to 

 the anterior end, in two small detached groups — 

 pterygoid teeth all small, forming a single, some- 

 what irregular series." Actually his two small de- 

 tached groups of palatines were one group (an- 

 terior) of palatines and one group (posterior) of 

 pterygoids, as is typical of the genus. The irregu- 

 lar series of pterygoid teeth is thus far unique in 

 this genus. They lie along the upper edge of the 

 bone for nearly its entire length (fig. 14 C) ; how- 

 ever, the size and number of these teeth may be in- 

 traspecifically variable. As mentioned, this fact 

 alone separates C. canina from other California 

 species, and, unless the type specimens of G. pallida 

 are found to contain such an arrangement of teeth 

 (all other characters being equal), the two forms 

 must certainly stand as distinct. 



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Figure 14. — Cyclothone. A, upper jaw of C. acclinidens showing the arrangement of teeth along the maxillary and 

 premaxillary ; the premaxillary is at the extreme left ; the long slender bone possessing most of the teeth is the 

 maxillary ; and the small bone at upper right is the supramaxillary. B, upper jaw of C. canina. C, palatine and 

 pterygoid bones of C. canina showing the unique row of teeth on the entopterygoid ; the anterior end is at the left. 

 D, posterior part of the first gill arch of Cyclothone sp. showing the typical arrangement of two gillrakers at the 

 angle. E, posterior part of the first gill arch of C. signata showing the unique arrangement of only one gillraker 

 at the angle of the epibranchial and eeratobranehial bones. F, branchiostegal membrane and rays of C. signata 

 showing photophore and pigment arrangement. G, branchiostegal membrane and rays of C. acclinidens showing 

 photophore and pigment arrangement. 



PELAGIC FISHES, CALIFORNIA CURRENT AREA 



645 



