112 NATURAL HISTORY OF 



occasions, and which also occurs at the Falkland Islands, 

 belongs to a genus of which the first species described was 

 found in the Arctic seas, and which appears to be specially 

 characteristic of northern and southern temperate and cold 

 latitudes. The test is generally thick and firm, and the 

 apertures are cruciform or lozenge-shaped. The former 

 mollusc I afterwards found to be abundant in the eastern 

 portion of the Strait, particularly in Possession Bay ; and I 

 never dredged it to the west of Port Famine, where the 

 largest specimen, which nearly equals one obtained by 

 Admiral Sulivan at the Falkland Islands, and which has 

 been described by Mr. Davidson, was procured. It is a very 

 fine shell, smooth, with both valves rather convex, and of an 

 oval form, and the largest specimen known (that in the 

 possession of Admiral Sulivan) measures over three inches 

 in length. Farther on in the season, I met with two other 

 species of Brachiopoda, both occurring in considerable 

 abundance — i.e. the Waldheimia dilatata and the Terebratella 

 Magellanica ; but neither of these species attains nearly such 

 large dimensions as the Waldheimia venosa. The ribbed 

 shell of the Terebratella varies much in form, being frequently 

 considerably distorted. 



On the following morning, Jan. 3d, I again left the ship 

 on an excursion, accompanying one of the surveying officers, 

 who had received instructions to examine that pa,rt of the 

 Patagonian coast extending between Cape Possession and 

 Dungeness Spit. Taking our departure between six and 

 seven A.M., we proceeded rapidly on our way for a consider- 

 able distance under sail ; but on nearing our destination the 

 wind was against us, so that we did not succeed in effecting 

 a landing on the beach, a little to the east of Cape Possession, 

 till between three and four p.m., at the expense of a tough pull 



