240 APPENDIX F.~ ARACHNIDIANS. 



longest; the poison bag is swollen up and provided with a slightly 

 curved and acute hollow spine. The upper part of each joint is concave 

 or grooved, whilst the inferior part is convex. They are carinated, and 

 rows of conspicuous granules are observed along the carinas. 



The color of the body above is uniform greenish yellow ; the thoracic 

 appendages (feet) are yellowish, whilst the palpi and caudal appendage 

 (tail) reflect a reddish shade upon the yellow ground. 



The specimen figured was collected in the valley of the Great Salt 

 Lake of Utah, by Capt. Howard Stansbury. 



A much smaller specimen was brought from Eagle Pass, Texas, by 

 Mr. Arthur Schott, of the United States and Mexican boundary. 



Plate XVI, fig. 5, represents, size of life, S. {Telegonus) boreus seen 

 from above. 



Fig. 6 is a view from beneath, to show the abdominal combs, first 

 abdominal segment, and origin of fourth and third pairs of feet. 



Fig. 1 represents the distribution of the ocelli. 



2. Scorpio (Atreus) californicus, Girard. 



General form of body and appendages slender when compared to the 

 preceding species. The tail is almost twice the length of the body; there 

 is not the same disproportion of length between the first and second joints 

 and the remaining ones. The carinas and rows of granules are much less 

 conspicuous. The cephalothorax and dorso-abdominal shields exhibit 

 carinas and rows of granules not only on the palpi, but likewise on the 

 feet. Rows of granules may be seen along the angular projections or 

 carinas. The chelae are much slenderer, the hand (carpus) and poison 

 bag much smaller. An exceedingly minute spine may be observed on 

 the poison bag under the sting. The lateral ocelli are situated more 

 anteriorly, more apart from each other, and equal amongst themselves. 

 The abdominal combs are composed of twenty laminae. 



Color light brown ; palpi and tail deeper ; upper part of abdomen 

 blackish, with a median light vitta. 



One specimen was collected in California and presented by Dr. Stone 

 to the Smithsonian Institution. 



3. Scorpio (Atreus) sati, Girard. 



Stn. — Buthus vittalus, Say, Jour. Acad. Nat. Sc. Philad. II, 1821, 

 61. 



