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XVI. Tivo remarhable forms of Mantid oothecae. By 

 R. Shelford, M.A, F.L.S., F.Z.S. 



[Read October 20th, 1909.] 



Plate XVIT. 



In a miscellaneous collection of insects formed by the late 

 Mr. F. P. Pascoe and recently presented to the Hope De- 

 partment, Oxford University Museum, by Miss Pascoe, was 

 found a box containing five Mantid oothecae from Delagoa 

 Bay. These specimens, together with an ootheca found 

 at Chamicuros, Peruvian Andes, by the late Edward 

 Bartlett and now in the Oxford Museum,* are so unlike 

 the usual type of Mantid egg-case, that descriptions and 

 figures of them will not be without interest. 



The East African specimens, which vary considerably in 

 size (30 mm. — 15 mm. in length x 14 mm. — 12 mm. in 

 diameter), are semi-transparent, bladder-like structures, 

 elongate-oval to almost spherical in shape and stra \v -yellow 

 in colour. Each is attached by a slender ring of parch- 

 ment-like consistency to the twig of a plant. The sub- 

 stance forming the walls of an ootheca also resembles very 

 thin parchment and is in direct continuity with the 

 attaching ring ; its surface is seen to be finely reticulated, 

 an appearance that is due to the inclusion of air-bubbles 

 in this dried and hardened secretion of the thecogenous 

 glands. The oothecae are firmly attached and stand out 

 from the twigs at varying angles. Along the middle line 

 on the upper surface of the ootheca there runs a Avell- 

 defined ridge. Tliis ridge is made up of a double series 

 of empty cells, 70 to 40 in number, open at the top but 

 closed at the bottom, so that they do not communicate 

 with the interior of the ootheca. The outer walls of these 

 cells are higher than the inner walls, the ridge, consequently, 

 when viewed from above, appears to be grooved ; the inner 

 cell-walls of one series interdigitate with the inner cell- 

 walls of the other series in a perfectly regular and sym- 



* The South American specimen bears the label " (^, $ and 

 nest," but I have not been able to tind the insects in the Hope 

 collection of Mantidae. 



TRANS. ENT. SOC. LOND. 1909. — PART IV. (DEC.) 



