NOTES ON JAMAICAN RHYNCHOTA. 71 



fresh material sent by Mr. Taylor, which confirms my opinion 

 expressed in the 'Bolletino Mus. Torino,' xiv. No. 350, pp. 5-6 

 (1899), viz. that Trochopus is not generically distinct from 

 Iihaf/ovelia. 



it may be useful to discuss the matter again briefly, and, 

 first of all, to reproduce a portion of the paper mentioned above, 

 which is possibly not very accessible to British entomologists : — 



" The chief differences between Rhagovelia and Trochopus 

 appear to be {teste Carpenter and Champion) that : 



" (1) In Trochopus the tarsi are (according to these authors) 

 3, 2, 2-segmentate ; in Rhagovelia 3, 3, 3. 



" (2) The pronotum in Trochopus is sutured off from the 

 mesonotum ; in Rhagovelia (except R. tenuipes, Champion, I. c. 

 p. 137) these nota are fused together. 



" (1) Now I have elsewhere expressed my opinion of the 

 unsatisfactory character of these minute tarsal 'segments.' I 

 think I may say that in average ' good ' museum specimens pre- 

 served in the ordinary way they are very difficult to observe with 

 any degree of certainty without a certain amount of preparation, 

 which is very undesirable, if not improper, in dealing with 

 borrowed material, especially types, and examination under a 

 compound microscope. The fact that such a careful worker and 

 able entomologist as Mr. Carpenter failed — in working with 

 material preserved in alcohol— in his original description {I. c. 

 p. 78) to detect more than two segments in each anterior tarsus 

 shows the undesirability of employing such a character. More- 

 over, these minute segments (or 'nodes,' as they may preferably 

 be termed) are apparently not always constant in the Gerrid£e, 

 for Prof. Uhler, in describing Trepohates pictiis (Proc. Zool. Soc. 

 Lond. 1894, p. 214), writes : — ' In two specimens the basal joint 

 of tarsi was present on one side, and not on the other.' 



" (2) The exception to the fused pro- and mesonota (in the 

 apterous R. tenuipes female) can scarcely be deemed to prove the 

 rule ; indeed, it appears almost to render further discussion un- 

 necessary. Moreover, a species from Venezuela in the Turin 

 Museum, which I have determined as R.femoralis, Champion, 

 and another from Venezuela and Darien, referred by me to 

 R. angustipes, Uhl., noticed in the first part of this paper), have 

 distinctly separated pro- and mesonota in both sexes, and at the 

 same time there are three distinct {as seen with a compound 

 microscope) segments in each tarsus. In short, Trochopus may 

 perhaps l3e on the way to developing into a new genus or sub- 

 genus, but it cannot be said, in my opinion, to have attained as 

 yet to that point." 



In examining the material sent by Mr. Taylor from the spot 

 where the original captures were made, differences in the seg- 

 mentation of the tarsi, similar to those mentioned by Prof. 



h2 



