LUBBOCK OX SPH^RULABTA BOMBI. 45 



ratus differs remarkably from that of the Nematoids, and I could remark no trace of 

 movement in any individual, — all of which were females, — however fresh I examined 

 them : the young ones, on the contrary, moved about in a lively manner. In this ani- 

 mal the interesting occurrence takes place, that the young are entirely unlike the full- 

 grown animal, their skin being quite smooth, while that of the mother animal is studded 

 with vesicular projections, giving to it a very pretty appearance." 



The only other original notice of this extraordinary creature which 

 I have met with is a note to Siebold and Stannius' ' ' Anatomie com- 

 paree." They say: — 



" On ne trouve ni bouche ni anus chez la Sphcerularia Bombi, et le canal intestinal 

 est remplace par une serie d'utricules allongees, adhereutes ensemble, et autour desquelles 

 s'enroulent les organes genitaux." 



Except that the series of large cells is double, instead of single, and 

 that one end of the worm is easily distinguishable by the presence of the 

 vulva, these statements are all, I believe, perfectly correct ; they still, 

 however, leave a great many points to be ascertained, and it was with a 

 hope of supplying the deficiency that I undertook the subject. My good 

 fortune has been smaller than my hopes ; but, though the present me- 

 moir is lamentably incomplete, it may not, I hope, be found entirely 

 without interest. 



M. Leon Dufour and Yon Siebold met with Sphaerularia in the 

 four species of humble bees — namely, Bomlus terrestris, hortorum, 

 sylvarum, and muscorum. I have found it in the females of B. terres- 

 tris, lueorum, pratorum, lapidarius, subterr emeus, hortorum, and mus- 

 corum, which increases to eight the number of species in which Sphae- 

 rularia is known more or less frequently to reside. The proportion of 

 specimens attacked is, however, very different in the different species, and 

 the parasite appears to be most common in B. terrestris, lapidarius, and 

 lueorum. Out of thirty-three specimens of B. terrestris examined by me 

 in the months of May and June, no less than nineteen — that is to say, 

 more than one-half — contained these parasites. The -following table 

 shows the number of bees examined, and the proportion which were 

 affected : — 



No. of large Females No. which contained 



examined in May and June. Sphterulari. 



Bombus terrestris .... 83 19 



,, lueorum ....21 7 



„ muscorum .... 16 1 



,, hortorum .... 13 1 



„ lapidarius .... 12 6 



,, pratorum .... 6-* 2 



,, subterraneus ... 4 2 



Apathus vestalis 7 



I have not had any opportunity of examining B. sylvarum ; and it 

 will be observed that B. muscorum and hortorum, in which the parasite 

 was found by Y. Siebold, have only supplied me with a single infected 

 specimen each, out of twenty-nine which I examined. 



Xeither Leon Dnfour nor Siebold say anything about the sex of 



