366 BULLETIN OF THE 



high latitudes in the breeding season as the fully adult. It is also 

 highly probable that, generally, the young birds of this family do not 

 range quite so far southward in winter as the older. The mature herring 

 gulls, so far as I had an opportunity of observing, far outnumbered 

 the young ones along the Carolina coast and on the St. John's River. 



173.t Larus delawarensis Ord. Ring-billed Gull. 

 " Not numerous." — Boardman. 



174* Chrcecocephalus atricilla Lawrence. Laughing Gull. 

 Common along the coast and on the Lower St. John's. 



175.t ChrCBCOCephalus Philadelphia Lawrence. Bonaparte's Gull. 

 With the preceding, and equally numerous. Also common, accord- 

 ing to Mr. Maynard, on Indian River. 



176.t Gelochelidon anglica Bonaparte. Marsh Tern. 

 Obtained by Mr. Maynard on Indian River. 



177.* Thalasseus regius Gambd. Royal Tern. 

 "Abundant about the coast." — Boardman. Maynard. 



178. Sterna hirundo Linn€. Common Tern. 

 " Common at Dummitt's." — Maynard. 



The following table of measurements of sixty-five specimens (forty-five 

 males and twenty females) of this species, taken in the breeding season at 

 Muskeget Island, Massachusetts, indicates the considerable range of indi- 

 vidual differentiation that obtains in this species. Though so great, it does 

 appear to be greater than occurs in Sterna macrura, of which I have the 

 measurements of twenty-five specimens taken at the same locality and dur- 

 ing the same excursion, nor is it probably greater than most of the terns 

 and gulls present, as is evidently indicated by the great number of 

 measurements of specimens of other species of the Laridm of our coast 

 now before me. 



The average dimensions of the specimens cited in the subjoined table 

 are as follows : — 



Males: Length, 14.51; alar extent, 30.72; wing, 10.47; tail, 5.80; cul- 

 men, 1.40; tarsus, .78. Females: Length, 13.85 ; alar extent, 30.59 ; wing, 

 10.57; tail, 5.74; culmen, 1.36; tarsus, .77. The extremes of the same 

 are as follows : — 



Males : Length, 13.00 to 15 77 ; alar extent, 29.00 to 32.00; wing, 9.65 

 to 11.70; tail, 5.00 (4.81?) to 7.00; bill (culmen), 1.28 to 1.55; tarsus, .70 

 to .87. 



