1887.] 45 



(pi. iii, fig. 5) does not indicate tliem. He worked almost entirely from fresh insects. 

 In my " Eevision and Synopsis," p. 512, I say of the conical lobe that the lanceolate 

 penis lies within it, and the apex of tlie organ (so considered) is indicated in my 

 figure, pi. Ivii, fig. 1. I worked only from dry material. Subsequently Mr. J. J. 

 King took commonly at Ambleside (and since then in several localities in Scotland) 

 a Hydropiila possessing most of the characters oi femoralis (and notably the dark 

 femora), in which the <? had the anal parts apparently similar, but there existed two 

 extraordinarily long spines proceeding from beneath the anal lobe, one nearly 

 straight, the other more or less spiral, both apparently chitinous. On this latter 

 character I founded H. longispina, McLach., in the "First Additional Supplement" 

 (1884) to my " Revision," p. 71, and what is no doubt an extreme condition is figured 

 there on pi. vii. Latterly Mr. King, when working out the enormous mass of 

 materials he had collected in Hi/droptilidcE, said that, in his opinion, based on his 

 materials, H. longispina should fall as a synonym of H. femoralis. And more 

 recently he forwarded a series of specimens from the same localities, some of which 

 should be tvwe femoralis, others true longispina, and others sufiiciently intermediate 

 to induce me to agree with him, unless the contrary can be proved. The " two long 

 setiform processes " described by Eaton (but which are not indicated in his figure, 

 and are not visible in his only dry $ type that I possess in good condition) no doubt 

 represent what I have considered the intromittent organ and its " sheath," the 

 latter being the spiral spine. A question of what may be termed " mechanical 

 anatomy " is involved. Notwithstanding the chitinous nature of these processes, 

 and their great length when fully extended, they must be retractile to an extent that 

 often prevents even the tips of them from being visible. In the case of the spiral 

 spine this could be arranged by coiling up, but the nearly straight one must (so I 

 think) often be absolutely retracted within the abdomen, a process that must need 

 powerful muscles and other internal organization scarcely possible to define owing 

 to the minute size of the insects. My original descriptions oi femoralis and longi- 

 spina otherwise agree remarkably ; even the number of joints in the antennse is 

 approximately the same in both, a point of some impoi'tance, considering the diffi- 

 culty of counting the joints in antennse such as these, and the almost practical 

 certainty that the number varies sliglitly in different individuals. — Id. 



Note on Strongylogaster macula, Klug. — Mr. McLachlan has sent me a speci- 

 men of this saw-fly, which he captured in his garden at Lewisham on ferns on the 

 5th of June. I have only once met with the species myself, viz., on the Kilpatrick 

 Hills towards the end of May, and, so far as I know, it has never been taken in 

 England before. I believe the species of Strongylogaster live but a very shoi't time 

 in the perfect state, and all, so far as our present knowledge goes, feed on ferns 

 during their larval existence. 



Kunow, it may be added, has formed a genus, Thrinax, for S. macula and its 



' allies ; and for S. delicatulus another new genus, Stromhoceros ; the name Strongy- 

 logaster being retained for filicis, cingulatus, and geniculatus (of Wiener Ent. Zeit., 

 iv, p. 19). To carry out this system logically it will be necessary to form more 



• genera for certain of the exotic species at present relegated to Strongylogaster. — 

 P. Cameron, Sale : June llth, 1887. 



