1914.] NATURAL SCIENCES OF PHILADELPHIA. 641 



s.m. on first discoidal cell, 480; second s.m. on third discoidal, 64; 

 lower side of third s.m., about 800; distance between lower end of 

 b.n. and upper end of t.m., 64. 



Wilson Ranch, Miocene shales of Florissant {H. F. Wickham). 

 Apparently a quite typical Andrena. It is easily known from A. 

 grandipes Ckll. and A. hypoUtha Ckll. by the venation. The venation 

 is like that of A. sepidta Ckll. and A. clavula Ckll., but these are much 

 smaller species, and clavida is also separated by the form of the 

 abdomen. 



Cladius petrinus u- sp. (Tenthredinidse). 



9. Length 7.5 mm., robust; antennae 3.65 mm. long, simple, 

 rather slender; width of head 1.85 mm.; head and posterior half of 

 thorax apparently black, rest of thorax and abdomen probably 

 reddish in life; wings clear, with very pale nervures; 4.25 mm. from 

 base of wing to middle of stigma. The end of the best wing is lost, 

 so that it is impossible to determine from it whether the marginal cell 

 has a cross-vein. The other wing is over the body and it is hard to 

 see the details, but the marginal nervure is sufficiently plain, and I 

 am confident that there is no cross-nervure. This accords with 

 Cladius, with which the rest of the wing closely agrees. The insect 

 runs in Rohwer's table {Bidl. Amer. Mus. N. Hist., XXIV, p. 521) to 

 20, and runs out on account of the character of the lanceolate cell. 

 If it had a marginal cross-nervure, it would run to Hemichroa eophila 

 Ckll., which is larger and otherwise dilTerent. There is no particular 

 resemblance to any more recently described species. Compared with 

 MacGillivray's figure of Cladius pectinicornis, the anterior wing 

 differs as follows: first s.m. longer; second t.c. bowed inward; t.m. 

 much beyond middle of second part of lanceolate cell ; end of second 

 r.n. only a very short distance beyond second t.c. It agrees in the 

 sides of the first discoidal cell being not at all parallel, the long and 

 narrow second discoidal, the very short upper side of first discoidal, 

 etc. The separation of the two parts of the lanceolate cell by a single 

 (coalesced) nervure is very short indeed, only 128 microns. 



The following measurements are in microns: length of first sub- 

 marginal cell (s.m.), 240; second s.m. on marginal, 928; first discoidal 

 on first s.m., 288 (the thickness of the nervures explains the difference 

 from the inside measurement of first s.m.); second s.m. on first 

 discoidal, 432; second s.m. on third discoidal (not allowing for the 

 strong curve), 1,040; third s.m. on third discoidal, 96; third s.m. 

 from second r.n. to end (apparently, from the obscurely preserved 

 wing), 656; first discoidal on basal nervure, 1,200; lower end of basal 



