THE DISCOBOLI. 53 



Color light olivaceous, puncticulate and clouded with brown to darker or 

 chocolate brown, snout and borders of fins darker ; caudal, and sometimes 

 dorsal and anal, with brown in irregular narrow transverse streaks. Largest 

 specimen five and three quarters inches in length. 



Hah. — San Francisco ; Monterey ; Coast of California ; St. Paul's, Alaska ; 

 Kamtchatka ; Plover Bay, Siberia ; Unalashka. 



Small specimens from St. Paul's differ from the above description in 

 having the median caudal rays somewhat more prolonged, the nasal region 

 less prominent and convex, and nebulous patches of brownish on the fins 

 and body ; all of which are no doubt modified with age. Some are much 

 darker than others. The fore part of the head appears narrower, and the 

 body in front of the vent much stouter, than in the larger specimens. 



Anatomy. 

 The skeleton in specimens of about six inches is nearly as firm as that 

 of the average teleostean. Due allowance must be made in all comparisons 

 on account of age. By comparing equal sizes, we find no great amount of 

 difference in the amount of ossification between the species of the subgenus 

 Liparis. On the larger individuals of L. mucosus the suborbital spine, about 

 three fifths of the length of the chain, is longer than on the young. The 

 comparative width of the expanded upper limb of the preoperculum also is 

 greater. Both the anterior and the posterior borders of the operculum 

 are curved ; the posterior extremity is elongate. The limbs of the inter- 

 operculum differ less in size and flexibility than in the preceding species. 

 Near the mid-length of the interoperculum there is a slight irregularity ; 

 otherwise the curvatures are almost regular in the two halves. Parie- 

 tals, frontals, paroccipitals, and exoccipitals are broad. The occipital crest 

 is short, but prominent. From the crest, in aged individuals, there is a 

 low ridge passing forward and bifurcating behind the frontal transverse 

 ridge. One of the more evident of the distinguishing features of this spe- 

 cies appears in the teeth, which are larger, with cusps less distinct and sharp, 

 and frequently so much worn as to look like blunted or rounded simple 

 crowns. Figure 5 of Plate V. represents the common form of tooth ; the 

 outlines on Plate IX. are from irregular and unusual ones. While the teeth 

 of L. mucosus are larger than those of L. calliodon, those of the latter are 

 really more harsh to the touch because of their sharpness. The plates 

 behind the last vertebra are short and broad ; the lateral ridges from the 



