1903.] NATURAL SCIEN'CES OF PHILADELPHIA. 129 



The Mode of Embrace in Copulation. — Grouping together my own 

 observations with those of other natiirahsts. and bracketing the author- 

 ity for each case, the following modes of embrace may be distinguished 

 in spiders: 



(1) — The male above the female with his ventral surface apposed to 

 her dorsal, their heads pointing in opposite directions, 



(a) — Female with her sternum down: Lycosa stonei, L. ocre'ata 

 pulchra, L. scutulata (Montgomery), L. monticola (Clerck), 

 L. amentata, L. rurestris (]\Ienge); Trochosa infernalis 

 (Lendl), T. terricola (Menge); Pardosa yiigr opal pis (Mont- 

 gomery) ; Sparassus (Bertkau) ; Epiblemum scenicum, 

 Attidcc, Enophrys reticulata (Menge), Attus scenicus 

 (De Geer) ; Plwurolithus festivus, MelanopJiora nocturna 

 (Menge). 



(b) — Female partially upon her side: Agalena ncevia (Emerton, 

 Montgomery), A. labyrinthica (Duges, Menge, Walck- 

 enaer), A. similis (Menge). 

 (2) — The head of the male facing the head of the female, their bodies 

 in one line, 



(a) — ^lale with his dorsum directed upward, female partially 

 upon her side: Tegenaria derhami (Montgomery). 



(6) — Both with ventral surfaces directed upward, bodies hori- 

 zontal: Linyphia marginata (Emerton, ]\IcCook), ?Stea- 

 toda boreal is (Emerton). 



(3) — Ventral surfaces of the pair apposed, sternum against sternum, 

 heads directed in opposite directions, 

 (a) — Copulation upon a web: Argenna (Bertkau), Linyphia mon- 



tana (Clerck), Linyphia triangularis (De Geer, Menge). 

 (b) — Copulation upon the ground, 



(&') — Male below the female: Argyroneta aquatica (Walck- 



enaer), Chiracanthium oncognathus (Menge). 

 {b") — Male above the female : Clubiona triviolis (Menge). 

 (4)- — Male holding to the side of the abdomen of the female, his long 



axis at right angles to hers: Acrosoma gracile (Montgomery). 

 (5) — Male with his ventral surface apposed to the posterior and ventral 

 surface of the abdomen of the female, their heads turned in 

 the same direction: Xysticus audax (Prach), A', triguttatus 

 (Emerton), X. stomachosus (Montgomery), Misumena vatia 

 (De Geer), Micrommata virescens (Menge). 

 (6) — Ventral surface of the male turned toward the ventral surface of 

 the female, their heads tiu*ned in the same direction, copula- 

 tion in a web, 

 (a) — Bodies not in actual contact, but heads converging: Epeira 

 labyrinthea (^Montgomery), E. diademata (Menge, Lendl), 

 Theridium tepidariorum, Pholcus phalangioides (IMont- 

 gomery). 



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