50 PROCEEDINGS OF UNITED STATES NATIONAL MUSEUM. 



Tbe type, No. 



-, Uuited States National Museum, was taken 



in a trawl-net outside of the Golden Gate, and was procured by us in 

 the San Francisco market. 



There are apparently three species of the genus Pleuroniclithys, as 

 restricted by Gill, in the waters of California. 



One of these is the common species in the San Francisco markets at 

 present, being taken in some abundance in the trawl-nets off Point 

 Eeyes and the Farallones. This species is the Pleuronichthi/s coenosus 

 of Lockington's Memoir (Proc. U. S. Nat. Mus. 1879, 97), and, as 

 Lockiugton suggests, it is probably identical with the Pleuronectes 

 quadrituberculatus of Pallas. For this form we accept provisionally 

 the name quadrituberculatus. 



A second species occurs farther south, two specimens having been 

 procured by us at Santa Catilina Island, and one at San Luis Obispo. 

 This form answers better than the ])receding to Girard's description 

 of his Pleuronichthys coenosus, and it may for the present be identified 

 with it. The specimen noticed by Lockington as " No. 4," " with the 

 dorsal not continued downward nearly so far as the others," perhaps 

 belongs to this species. 



The third species is P. verticalis, described above. 



The species may be readilj' sepai'ated, so far as we have observed, by 

 the following characters : 



•Dorsal fin begiuuing on the level of the lower lip, about ten of its anterior rays 

 being on the left side ; ocular region with four or more blunt prominences or 

 tubercles, arranged as follows: one in front of upper eye, another at each end 

 of the interorbital ridge, the posterior largest, but not spine-like, one behind 

 the latter, and one or two more behind the upper eye ; upper part of opercle 

 uneven; lower jaws with a band of teeth on the right side similar to that on 

 the left side, but narrower; fins high, D. 72, A. 46 Quadrituberculatus. 



* * Dorsal fins beginning on the level of the ui)j)er lip, only four or five of its rays being 

 on the left side of the median line. 

 t Posterior prominence of interocular ridge developed as a strong backward- 

 directed spine ; tubercular prominences present about the upper eye ; no teeth 



on right side of lower j aw ; fins rather low, D. 65, A. 45 Verticalis. 



tt Posterior prominence of interocular ridge scarcely elevated ; other dcular tuber- 

 cles obsolete; teeth ?; fins high, D. 68, A. 48 Ccenosus. 



Measurements. 



Verticalis. 



QitadriUiberculatui. 



Kxtreme length, in inches 



Length to base of caudal, in inches = 1.00 



1^0(1 J', f^reatent depth 



Body, least depth of tail 



Head, length 



Head, diameter of orbit 



Dorsal, distance from first ray to median line 



Dorsal, greatest height 



Anal, greatest height 



Caudal, length 



I'cctoral, length 



Ventral, length 



9.20 



7. 50 = 1.00 

 .54 

 .U 

 .24 

 .07 

 .055 

 .13 

 .13 

 .255 

 .135 

 .11 



11.85 



9. 20 = 1. 00 

 .62 

 .13 

 .28 

 .083 

 .11 

 .19 

 .18 

 .28 

 .18 

 .11 



