1889.] natural sciences of philadelphia. 45 



March 5. 

 The President, Dr. Jos. Leidy, in the chair. 

 Seventeen persons present. 



Note on Gonyleptes and Solpuga. — Dr. Leidy exhibited a curious 

 spider, presented by Dr. W. H. Jones, who obtained it in Rimac 

 valley, in the vicinity of Lima, Peru. It is a large form related to 

 our Daddy-long-legs, Phalangium, and is the Gonyleptes curvipes. 

 The species was originally described from Chili. It is represented 

 in Fig. 176, in Kingsley's Standard Natural History. 



Another specimen exhibited, was presentee! by Mr. Joseph Will- 

 cox, who collected it in Florida. It is a Solpuga, differing from 

 ordinary spiders in having both thorax and abdomen segmented. 

 The species, according to Putnam (Proc. Davenport Acad. 1883, 

 264), was previously collected in the same locality, It agrees in 

 size, 20 mm., and other characters, with the Galeodes cubce, of Cuba, 

 described by Lucas (Hist, de l'Isle de Cuba, Atlas, Tab. v., fig. 6.) 



Mazapilite, a. new mineral species. — Prof. George A. Kodnig re- 

 called to the Academy, that he had given a preliminary notice on 

 July 3, 1888, of a new mineral of which he had not yet made a 

 quantitative analysis or measured the angles accurately, as he was 

 then on the point of leaving for his summer vacation. The mineral 

 was then described as an arsenite of iron and calcium. The full ex- 

 amination showed this description to be erroneous. When first 

 examined the mineral yielded in the closed tube a sublimate of 

 As 2 O 3 and water. This sublimate was not obtained in repeated 

 later trials. The mineral is an arseniate of calcium and iron. 



Mazapilite occurs only in well-developed crystals, which are im- 

 bedded in white calcite and aragonite. The crystals vary in length 

 from ? to & inch, and rV to to inch in breadth. They are all de- 

 veloped at both ends and fall easily from the matrix, in which they 

 leave an ochre-yellow impression. Minute warty particles of a gray- 

 ish color were observed in some of these cavities. 



The crystals are black, deep brown-red on the fracture. They are 

 slightly translucent at the thinnest edges with blood-red color. 



The streak is ochre-yellow. The luster is submetallic. 



The crystals possess the habitus of the combination represented in 

 the cut, without exception. 



The four faces designated( ^ P) are found to lie in one zone and 

 therefore the symmetry of the combination is orthorhombic. 



The following angles were measured : 



P: P = 115° 10' (over oo P.) 



P : P == 100° 35' (over brachi-axis.) 



