596 Mr. D. Sharp and Mr. F. Muir on the Comparative 



tusks of the lateral lobes slightly shorter, and the consolidation of 

 the two lobes where they meet in the middle behind the ventral 

 plate very short. 



One example (Cochin China, old coll.) of the same development 

 as the two moderate Koberi forms, differs from them in having the 

 ring of the lateral lobes considerably narrower, the tusks a little 

 longer, and separated by an interval of rather different form. The 

 difference from the Koberi high development male is even slighter. 



One specimen from Aniboina (F. Muir), a small development but 

 not the smallest, has a decidedly different shape of the orifice, which 

 may be described by saying that above it resembles a Gothic arch, 

 while the forms previously mentioned are more like a Norman arch. 

 Still more striking is the fact that the membrane above and in front 

 of this arch is strongly chitinised, quite black, and the ventral plate 

 is extensively chitinised. 



One specimen {" Malasia," old coll.) of maximum development 

 as regards cephalic and thoracic armature, but a rather small and 

 slender individual, differs slightly from the Koberi moderate form 

 in having the distal cylinder of the tambour more slender, and as a 

 consequence the orifice between the lateral lobes more contracted ; 

 the tusks are a little longer, and the area between them is narrower 

 and of slightly different form. 



An individual ("Ter" [nate] Wallace I believe) is of almost the 

 smallest development of the species, being with cephalic horn only 

 about 30 mm. long ; it approximates the Amboina individual, but 

 entirely lacks the hard chitinisation of that specimen. 



The sac, in these exam^jles, has not been adequately examined, 

 but in the specimen from Cochin China the curious pair of large 

 spines on it appear to be more inequal in size than they are in the 

 others. 



Whether any racial distinctions are to be found in these male 

 structures can be decided only by the examination of good series. 

 We see no reason for supposing that any of the distinctions are of 

 specific importance. The extreme chitinisation of the parts in the 

 Amboina individual is remarkable. In it and in the Teruate example 

 the two spines on the sac are nearly of one size. 



Aitgosoma centaurus. 



Very like X. gideon but the points of the lateral lobes are acute, 

 and pressed together to their tips and turn downwards ; the 

 ventral plate of the basal-piece is consolidated to the lateral 

 lobes ; the internal sac is large and has no spines, but has at least 

 one long diverticulum. The conjoined struts at the base of the 



