138 Mr. C. J. With on Clielonethi 



abnormal segmentation found in Arachnids, Insects, and 

 Annelids : — 



Arachnids. — In Hansen and Sorenseii's paper (24, p. 97, 

 pi. ii. fi^. 2 fl) I came across a figure of Stylocellus suma- 

 tranus, Westw., one of the Cyphophthalmi, which shows that 

 the groove between the fifth and the sixth tergite on the left 

 side is incomplete ; a kind of split segment is thus formed. 

 If the right half of the sixth tergite is fused with and undis- 

 tiuguishable from the right part of the fifth the abnormality 

 is of another nature than that found in Ch.javanus ; but if 

 it is connected with the right half of the seventh tergite the 

 similarity to the above-described case is unmistakable. 



Insects. — In the collections of the British Museum I found 

 some specimens of Hymenoptera showing abnormalities in 

 the segmentation. By the kind assistance of Col. Bingham 

 I am able to give the names of the insects iu question. In 

 Trans. Ent. Soc. (23) I found a short note about one of these 

 animals by the Rev. F. D. Morice, who had collected the 

 specimens. He exhibited to the Society a specimen of 

 " Gorytes quinguecinctus (fossor) with the abdominal segments 

 twisted out of their proper shape and place." The animal 

 so named is, according to Col. Bingham, not a Gorytes, but 

 Cerceris quinquefasciata. The cases are the following : — 



1. Polistes sp. — The first and the second segments are 

 normal, the latter being provided with the usual yellow spots 

 and marginal band, but the two following tergites are irre- 

 gular. The left side of the third passes without any limita- 

 tion "whatever into the right side of the fourth, and so does 

 the yellow band along the hindmost margin, which is directed 

 obliquely backwards. The right portion of the third tergite, 

 ■which is bordered with yellow, is well separated from the left 

 and is short and narrow. The left portion of the fourth is 

 even less marked, almost triangular, bordered with yellow', 

 and without communication with its right part or with the 

 fifth tergite. The latter is almost normal if the irregularly 

 shaped anterior and posterior margins be excepted. Ven- 

 trally and laterally the segmentation appears normal. 



2. Megachile sp. — The dorsal side shows the following 

 abnormalities : — The hindmost margin of the third segment 

 is not quite transverse, but slightly oblique, so that its right 

 side becomes longer than its left. The left halves of ttic 

 fourth and the fifth segments, which are well separated by a 



