354 Records of the Indian Museum. [Vol. VI, 



this factor has been ascertained, it seems best to refrain from 

 further additions to the nomenclature. 



The Bulandshahr specimens range from 30 to 40 mm. in 

 length excluding the f ureal rami and according to Major Walton 

 the average length of all obtained is 33 mm. In a perfect indivi- 

 dual 30 mm. in length, the length of the shield in the middle line 

 is 22 mm., that of the median carina 16 mm. and that -i the furcal 

 rami 29 mm.^ The long ramus or fifth endite of the first trunk- 

 limbs reaches well be3"ond the posterior extremity of the shield ; 

 it measures 22 "5 mm. in length and is composed of about 58 

 segments. 



On comparison the appendages were found to agree very 

 closely with those of specimens of A. cancriformis from Lombardy 

 and with those figured by Lankester"^ from examples obtained at 

 Munich. Prag and Padua. The segments of the first trunk-limbs, 

 while distinctly longer than is indicated in Lankester's figure, are 

 similar to those of the Italian specimens. As regards the number 

 of these segments there again appears to be considerable varia- 

 tion. Lankester gives the number as 80, but Packard^ states 

 there are only 50 and points to the greater number (80) found in 

 A. hi iua lay anus as an important feature of that species. In the 

 Bulandshahr specimens, as mentioned above, the number does not 

 seem to exceed 60 and in this respect direct comparison with the 

 Italian examples in the Museum collection is unfortunately im- 

 possible, for in them these appendages are all broken. 



In the specific determination of Apodidae great .significance 

 has been attributed to the length of the body as shown by the 

 number of segments uncovered dorsally behind the median notch 

 of the carapace and ventrally behind the last pair of trunk- 

 appendages. Perhaps too much stress has been laid on the former 

 character, for, while it is true that in certain cases it affords a 

 very obvious distinction between species, it seems that it is to 

 some extent dependant on the amount of shrinkage that has taken 

 I)lace during preservation, and a glance at Wolf's figures of 

 Lepidurus viridis, vars. clongatus and setosus* 3delds convincing 

 proof of the great variation of this character within the limits of 

 a single species. In the Bulandshahr specimens from 8 — 11 seg- 

 ments are exposed in dorsal view. 



The number of segments seen from below behind the last 

 pair of trunk-limbs appears to constitute a more valuable feature ; 

 five such segments are found in Major Walton's specimens and 

 five also occur in the Italian examples of A. cancriformis. Accord- 

 ing to Packard {loc. cit.) there are six in this species, while Braem^ 

 found that in females from the neighbourhood of Breslau the 

 number varied from five to seven. 



J See also the other niea.surcinents given by Walton, anlii, p. 352. 

 ^ Q J. Micr. Sci (n, s.), xxi, p. 343, pi. xx (1881). 



5 Ann. Mag. Nat. Hist. (4). viii, p. 335 (1871). 



* Wolf, Fauna Sifdwest A ustraliens, iii, If. 9, pp. 267 — 9, text-figs. 11, 13 



6 Braein, Zeitschy. Wiss. Zool., Ivi. p. 183 (1893). 



