56 HELLER 



The most distinctive feature of the skull in our specimens is found 

 in the tympanic cavity, which is bordered posteriorly by a prominent 

 process just above the notch made by the Eustachian tube, causing the 

 notch to appear very deejo. The pterygoid edges are moderately 

 flattened. The occipital condyle is large and preceded by a wide 

 open cavity. 



The carapace is usually striated in the young, but in the adults this 

 character is nearly or quite lost, only a few striations appearing, in 

 some specimens, on the margins of the plates. A few large males 

 were seen that had conspicuously striated plates, from which it is in- 

 ferred that striation has no specific value but is merely due to individual 

 variation. 



TESTUDO MICROPHYES Giinther. 



Testudo microphyes Gunth. Phil. Trans., CLXV, p. 275, 1875, and Gig. Land 

 Tort., p. 78, pis. xxxii-xxxviii and xlii-xlv, 1877. — Boul., Cat. 

 Chel. Brit. Mus., p. 170, 1889. — Baur, Am. Nat., xxiii, p. 1044, 1889. 



(.?) Testudo nigrita Lucas, Smith. Rapt., p. 643, pi. civ, 1889 (figure resem- 

 bles T. vicina rather than this species). 



Range. — Albemarle Island; Tagus Cove and the slopes of the 

 adjacent volcano (Petrel, Hopkins Stanford Expedition). 



None are now to be found in the immediate vacinity of Tagus 

 Cove where apparently they have been extinct for a considerable time. 

 A few may still be found a short distance inland on the sides of the 

 adjacent volcano. During several weeks' exploration on the western 

 side of this volcano not more than seven or eight tortoises were met 

 with and these were all adult males. They range vertically from 

 near sea level to the rim of the volcano, 4,000 feet. The absence of 

 young might be accounted for by the destruction of the eggs by wild 

 dogs but why no females were found is unaccountable. The report 

 by whalers that tortoises occur on the northern volcano of Albemarle 

 makes it probable that this species ranges to Point Albemarle as the 

 two volcanoes are not separated by any wide stretch of impassable 

 lava. The Ecuadorians report a species of tortoise on Cowley vol- 

 cano which if this form, as seems very probable, indicates a distribu- 

 tion as far south as Perry Isthmus. 



In comparison with the Iguana Cove form, 7. vicina, this species 

 is more elongate with longer limbs and higher carapace which, 

 in the male, has a flaring anterior border as in the Duncan Island 

 form. This difference in shape may be due to difference in climatic 

 conditions. Tagus Cove being dry and desert-like, with well marked 

 wet and dry seasons, could support only an active long limbed species 

 that could do much foraging during the long dry season. 



