244 ENTOMOLOGICAL NEWS. [J^ly, 'l8 



Wesfei scHEiD, Hejxrich. igi2 — Ueber die Biologic und Anatomic 



von Plea minutissima Leach. Zoologische Jahrbiicher, Jena, 



XXXIII, p. 387. 

 Wesenberg-Lund, C. 1913. — Fortpflanzungs-verhaltnisse; Paarung 



und Eiablage der Siisswasserinsekten. Fortschritte der Naturwissen- 



schaftlichen Forschung, VIII, p. 195. 



EXPL.A.XATIOX OF Plates XIV and XV. 

 Plate XIV. 

 Fig. I. Ventral view of the genitalia of the female .V. irrorata show- 

 ing the drilling parts of the ovipositor — indicated by V. It is 

 one of these parts that is figured from three aspects in Plate 

 XV. figure 9. 

 Pig. 2. A portion of water-soaked cattail leaf showing two eggs of 



A', irrorata deposited through one puncture. 

 Fig. 3. Egg of A^ irrorata in Moneywort stem. The embryos usually 

 develop with cephalic end at micropylar pole of the egg. This 

 one is reversed as shown by the eyespot of the developing 

 nymph within. 

 Fig. 4. Egg in Moneywort showing the nature of the rent through 



which the nymph escaped. Postnatal molt removed. 

 Fig. 5. \"entral view of the genitalia of the female A", insulata, show- 

 ing the drilling parts of the ovipositor — indicated by V. It is 

 one of these parts that is figured from three aspects in Plate 

 XV, figure 5. 



Plate XV. 

 This plate contains three views of the left member of the first pair 

 of gonapophyses of the female of each of the species of the genus 

 Motonecta available in this country. Two species have been omitted 

 because of the lack of material. 



The views are from left to right: Outside or lateral view — ven- 

 tral view showing the organ on edge — Inner view. All of the draw- 

 ings were made with camera lucida and drawn to the same scale. The 

 length of the adult, together with outside measurements of the ovi- 

 positor are added for purposes of comparison of relative size of 

 parts. The writer believes that a study of these organs should be 

 taken into account in determining relationship of species. A study of 

 a wide series would certainly establish the range of variability in size 

 and shape of these parts and ii\ some cases (if not all) aid in specific 

 determinations. The drawings here presented are, however, intended 

 to indicate merely the correlation of this organ with the habit of 

 oviposition. 



Fig. I. Notonecta lutea. Size of adult, 13-17.1 mm. ; valve of ovi- 

 positor, 1.625 mm. X .725 mm. Specimen loaned by Mr. Gib- 

 son, of Nat. Mus. Taken in Finland by Sahlberg and determined 

 by Kirkaldy. 



