IIYDRACARINA 87 



Williamson (1920, p. Ill; 1925, p. 59) now regard this form as the same species as 

 E. hamata. Lastly Uaday, in the same year (1901) in his monograph on the Hungarian 

 Eylais-specics, published the description of a supposed new species, E. longipons, which 

 almost exactly agrees with E. gcorgei Soar, having an eyeliridge of the same shape. I do not 

 hesitate in considering this form a real hamata. The broad and short maxillary plate, the 

 immense overlapping pharynx with its distal hooks and the great mouth-disc indicate that 

 both forms are identical. The third palp-segment is more conspicuously protruded than in 

 hamata, but 1 think this character is referable to a mistake, like so many others in Daday's 

 drawings. Walter's var. alpina, finally, is merely a dwarfed form of hamata and in all other 

 respects quite typical. 



E. hamata is an easily recognizable though rather varialjle species. The specific features 

 are to be found mainly in the eyeplate, the maxillary organ, the last palp-segment and, as 

 pointed out by Thon (1905, p. 158; 1906, p. 15, p. 45), in the structure of the epimera. The 

 eyebridge is always very long, but length, as w-ell as width, is variable. The maxillary 

 organ is always broad, with a short maxillary plate, a broad and immense mouth-plate and an 

 overlapping, hook-bearing, distally widened and rounded pharyn.x. The end-nails of the last 

 palp-segment are very blunt. The epimera present a close mesh-work of chitinous balks of 

 various thickness, quite different from those of most other species. A drawing may serve to 

 illustrate this peculiar structure. The thicker main balks always connect the front and the 

 hind margins {i.e. the longer sides) of the epimera, whereas the thinner balks run in dif- 

 ferent directions Ijetween the main balks. Lately I have drawn the attention to a somewhat 

 similar structure in E. iiintila Koen. (Lundblad, 1929, pp. 5-6.) In this species, however, 

 the epimera are still more chitinized, the meshes being reduced to narrow pores, so that no 

 balks can he distinguished. In E. hamata the structure of the epimera varies greatly, in some 

 examples no distinction can be made between main balks and secondary balks, the meshes 

 sometimes lacing more or less pore-like, though not so narrow as in E. mutila. Also the 

 nymphs of the two species in question are distinguished by the same respective characters. 

 In other species of Eylais there is no real meshwork, only main balks with some few connect- 

 ing secondary balks between them being developed (cf., for instance, Thon, 1906, p. 69: 

 E lati pons and p. 72: E. ineridionalis. Lundblad, 1929, Plate III, fig. 19: E. discreta). 



Regarding all characteristics mentioned above, the present specimens are quite typical 

 hamata. All examples are females. The male possesses two semicircular genital plates like 

 most other species of the genus, whereas the female is destitute of real plates. Her genital 

 opening is surrounded in front by a great numlaer of long bristles. Originating from the 

 opening there is a subdermal, suture-like, chitinous rod directed backwards. Some short and 

 strong bristles are inserted in the skin on each side of the rod. 



Locality. Indian Tibet: near Chu.shol, altitude ca. 4,340 m. 14 Julv, 1932. 



Distribution. Most European countries, Palestine, Asia Minor, .Siberia. In Switzerland 

 it is fijuiul at 2450 m. above sea level (Walter, 1922, p. 247). 



