DIPXEROUS FAMILY PANTOPHTUALMID^. 587 



two 2 2 from the Bigot collection, presented to the British 

 Museum by Mr. Collin. 



The c? find 5 in the British Museum, collected respectively 

 by H. W. Bates and Mrs. Noel, are each pseudo-pai-asitized by 

 nymphs of the usual species of Gamasid mite. In the case of 

 the c5' , there is only a single Acarid, which is on the upper 

 surface of the abdomen ; the pseudo-parasites on the $ are 

 present on both sides of the abdomen, and, although only in 

 small numbers, aie more plentiful above than below. One of the 

 specimens in the Oxford collection is similarly infested. 



Pantophthalmus bellardii Bell. 



Acanthomera hellardii Bellardi, Saggio di Ditterol. Messicana, 

 Appendice, p. 16, Tav. iii. fig. 11 (1862). 



Acanthomera championi Osten Sacken, Biol. Centr.-Amer., 

 Diptera, vol. i. p. 67, Tab. iii. fig. 16 (1886). [New synonym.] 



Paniophthalmus helleri Enderlein, Zool. Anz., Bd. xli. no. 3, 

 pp. 108, 110, (igs. 8, 1) (Dec. 20, 1912). 



Although nothing can be said with reference to the male of 

 P. hellardii, since it is at present unknown, in the female sex, 

 as shown by the extensive series of specimens available to the 

 writer for comparison, the species is normally one of the finest 

 of its family, and is conspicuous, even among the huge Diptera 

 with which this paper is concerned, as much on account of the 

 dark coloration of the body and wings, as by reason of the shape 

 of its shining abdomen. While females of P. bellai'dii of ordinary 

 size are certainly not larger — perhaps if anything actually less 

 bulky — than corresponding examples of P. tahaninus Thunb., 

 the great breadth often exhibited by the flat abdomen, combined 

 with the shining black surface of the first four abdominal tergites 

 (except the base, hind border and lateral extremities of the first, 

 and the hind borders and lateral extremities of the remainder), 

 serves to make the present species noticeable among its congeners, 

 among which, in actual size of the largest examples, females of 

 P. tahaninus are its only rivals. It is therefore not a little 

 curious, as well as unfortunate, that the holotype of P. hellardii 

 — formerly in the Bigot collection, and generously presented to 

 the British Museum (Natural History) by Mr. J. E. Collin, 

 F.E.S.— is one of the smallest Pantophthalmids yet seen. The 

 dimensions of a large female of P. hellardii in the National 

 Collection are as follows : — Total length (ovipositor and short, 

 blunt, facial beak included) 53'5 mm.; greatest breadth (measured 

 across the third abdominal segment) 20'o mm.; wing-expanse 

 86 mm. (nearly 3|^ inches). The corresponding measurements 

 in the case of the type are respectively 24, 9*5, and 43 mm. 

 Moreover, apart from its diminutive proportions, the type of 

 P. hellardii is anything but typical, since it is faded, rubbed, and 

 somewhat shrunken, having in all probability originally been 

 preserved in spirit before being pinned. Nevertheless, the 



