Mammals of ttik mf.xicax boundary. 121 



peared for the firsi time since Leaving the Lesna and Cobota moun- 

 tains. This agave was only seen in the Tule Mountains of Arizona 

 and Sonora. The plant is about the size of Agave lechuguilla 

 Torrey, with something of the appearance of Agave applanata 

 parryi (Engelmann) Mulford. The broad leaves have fleshy mar- 

 gins and remarkably stout, deflected spines, which spring from the 

 margins of the leaf, which is similar to thai of parryi in shape, glau- 

 cous, and armed with an indurated terminal spine about 25 mm. in 

 length. The flower-stalk is 1 to 3 meters in height and resembles that 

 of Agave applanata parryi. It was not seen in flower. Mesquites 

 here grow to a considerable size, in canyons, and develope a spread- 

 ing habit of growth, the branches forming elbows which reach the 

 ground and are often buried in the sand, the extremities again ascend- 

 ing. The palo verde is uncommon; but the small-leaf horse bean is 

 abundant, growing up the mountain slopes and canyons, as well as on 

 arroyos, though sparingly in the hills. The Sonoran ironwood as- 

 cends to the mountain tops. In the bed of a sandy arroyo the indigo 

 thorn, in one instance, became a tree one-third meter (1 foot) in 

 diameter and 7.3 meters (ii4 feet) in height. E chinoeactus wisliseni, 

 which was not seen west of the Sonoyta, was here replaced by Echino- 

 cactus lecontei, which was not seen east of Quitobaquita, where both 

 occurred. A cactus was first found here, growing in the form of a 

 mound, like a pyramid of cannon balls, each as large as a coconut. 

 It occupied smooth slopes of bare ground, covered with small chips 

 of volcanic rock. There were other new forms of cacti, among 

 them a coarse Cylindropuntia Inning whitish spines; this first ap- 

 peared in the Sierra de la Salada, and. in the desert ranges to the 

 westward, became the prevailing cactus and the chief food plant of 

 the mountain sheep. A very singular plant i^ Terebinthus micro- 

 phylla (Gray) Rose (Bursera microphylla Gray), which has the ap- 

 pearance of a stout, woody shrub, but is so soft and spongy that when 

 a plant dies it melts down like a cactus and goes to pieces instead of 

 drying hard in its natural form. 



Reptiles. — It was said by several members of the surveying party 

 that gila monsters of a kind different from those at San Bernardino, 

 Monument No. 77 (Heloderma suspectum Cope), were numerous in 

 the Tule and Tinajas mountains, which were surveyed in April and 

 May. At the time of our visit (February) the only reptile much in 

 evidence was the Uta stansburiana, which is often active when the 

 temperature is quite low: but Mr. Joe IT. Wheeler, who was the 

 most accurate observer of the civilian employees of the survey, wrote 

 me, in April, is'.).",, that he found: 



Lizards, very large, 18 to 24 indies in length; hacks of a brick-red color; 

 legs and head black; tail gray or granite color, and not very tapering; belly 

 and breast reddish, and gray tinted on sides. 



