EOPERIPATUS BUTLERI. 543 



the larger ones in the distal third, which would bring the 

 number of rings — both large and small — up to fifty or fifty- 

 one. 



The Jaws. — The outer blade of the jaws has the same 

 structure in E. Butleri as in E. Horsti and E. Weldoni; 

 that is, there are two small denticles on the inner side of the 

 main tooth (fig. 6). The inner blade, however, dijffers from 

 that of the above-mentioned species in that it has three small 

 denticles, instead of two, between the main tooth and the 

 diastema, as well as fourteen smaller denticles on the inner 

 side of the diastema instead of the nine or ten found in E. 

 Weldoni and B. Horsti (fig. 7). The jaw-blades are larger 

 in E. Butleri than in the other species. 



The Oral Papillae. — Tiie oral papillae are in no way 

 peculiar. They consist of two rings which do not carry 

 papillae, and of an end-knob which is provided with papillge 

 mainly on the dorsal aspect. The opening of the slime-gland 

 is slightly sub-terminal. 



The Legs. — There are twenty-four pairs of legs, which 

 are arranged as in the species Horsti, with almost the same 

 distance between the successive pairs of feet along the whole 

 length of the body, with the exception of the last two or three 

 pairs; a feature which distinguishes E. Butleri, even at a 

 glance, from E. Weldoni, in addition to the fact that the 

 legs are shorter and stouter. The legs, with the exception 

 of the last two pairs, are provided with four pads, and many 

 of those situated behind the fifth pair have a vestige 

 of an additional one (fig. 2). The penultimate pair has only 

 three pads, which are reduced on the last pair to two. 

 On neither of the last two pairs of legs are the pads well 

 separated from one another. 



Crural grooves occur on all the legs, but are least developed 

 on the first pair, where they are hardly visible. On the distal 

 angle of these grooves there is a whitish structure, which may 

 consist of two papillas lying close together, or of an U-shaped 

 body formed by the fusion of the two papillae on their distal 

 side. They seem to occur on all the legs, though owing to 



