624 MR. W. N. PARKER ON THE CiECUM IN [May 3, 



of black irroratious : secondaries silvery white with pearly reflections : 

 body snow-white. Wings below sordid white with faint golden reflec- 

 tion's ; body -white. Expanse of wings 10 hnes. 

 One specimen. Kurrachee, July 1880. 



104. Eriocottis fuscanella? 

 Eriocoitis fuscanella, Zeller, Isis, p. 813 (1847). 

 Two worn specimens. Kurrachee, May 1880. 

 The types and all the better examples in this series of Lepidoptera 

 are incorporated with the national collection. 



8. Note on some Points in the Anatomy of the Caecum in 

 the Rabbit [Lepus cuniculus) and Hare [Lepus timidus) . 

 By W. N. Parker, Assistant in the Biological Labora- 

 tory of the Royal School of Mines. 



[Eeceived March 15, 1881.] 

 (Plate LIII.) 



Some few months ago Prof. Huxley called my attention to the 

 fact that Krause's description of the relations of the ileum and sac- 

 culus rotundus to the caecum in the Rabbit (Anatomic des Kanin- 

 chens, pp. 156, 1.57) was incorrect, and proposed that I should look 

 the matter up. I therefore examined the structure of these parts 

 again, not only in the Rabbit, but also in the Hare, and in doing so 

 noted the following resemblances and differences. 



In both the caecum, as is usual in grass-eating mammals which 

 have a comparatively simple stomach, is of a relatively enormous 

 size, being on an average, when straightened out, about 1 foot 8 inches 

 long in a moderate-sized Rabbit, and rather more in the Hare. This 

 measurement includes the appendix vermiformis, which varies from 

 about ^\ to 4i inches in length. 



The ileum appears externally, in both species, to pass directly into 

 the sacculus rotundus, at right angles to the long axis of the caecum. 

 The sacculus has an ovoidal shape, its long axis being transverse to 

 the long axis of the caecum in the Rabbit (fig. iv.), but longitudinal 

 in the Hare (fig. ii.) 



In both also the caecum passes insensibly into the colon, which 

 runs straight from it for about 2 or 2| inches, and then makes a 

 sudden bend in the opposite direction, taking on the characteristic 

 form, with the sacculations and the three teenice coli. 



Daubenton (Histoire Naturelle, tome sixieme) describes the sac- 

 culus as a pocket near the junction of the ileum with the colon, and 

 gives figures (pis. xl., xh. pp. 273, 274), of the Hare's caecum both en- 

 tire and cut open, the latter showirjg the two distinct apertures of the 

 sacculus and ileum into the colon (fig. i. s.c, i.c) ; but he gives no 

 details on this point in the Rabbit (p. 321). Krause describes these 



