I go The Irish Naturalist. 



light has been thrown upon the question of this worm's identity from an 

 unexpected quarter. I wrote some months ago to Dr. Rosa, the Italian 

 helminthologist, respecting the species under consideration, and learned 

 in reply that there was undoubtedly a close affinity between it and a 

 species or variety {A. veneta) which he had discovered at the same time 

 on the Continent. 



Dr. Rosa has, within the past few days, favoured me with a copy of his 

 newest work on the subject of Earthworms, and in this volume (Revis- 

 tone del Lumbricidi, 1893, p. 34) he does me the honour to print a full 

 account of the Irish worm as a sub-species of Allolobophora veneta, Rosa. 



Allolobophora hibernica, Friend. — Irish Worm. When living, 

 and extended in the act of crawling, the worm is about 50 mm. or two 

 inches in length. In spirits it is from one to one and a-half inches, or 25 

 to 35 mm. long, and thus ranks in size with three or four of our British 

 dendrob£enic worms, such as the Tree- worm i^A. arborea, Eisen), or the 

 Celtic Worm {A. celtica, Rosa). Unlike those, however, its colour is fleet- 

 ing, so that immediately upon being placed in alcohol the small quantity 

 of colouring matter which is present in the living worm evanesces, leaving 

 the preserved animal without the least indication of its pretty appearance 

 in a state of nature. The anterior portion of the worm when alive is of a 

 rosy hue, closely approaching flesh-colour; the girdle is of a dull yellow, 

 while the rest of the body, excepting the caudal extremity; is a greyish 

 hue, appearing brown along the line of the dorsal vessel. The last half- 

 dozen segments are yellow, just as in the Gilt-tail or Cockspur of the 

 angler {^A. subrubicimda, Eisen). The presence of a pigment, which is ex- 

 uded from the dorsal pores, accounts for this yellow tinge, which in the 

 most adult specimens may be found pervading other portions of the body 

 to a slight degree. 



With a worm so short as this, it is rather unexpected to find so many 

 segments, but the average is 90-100, so that they are very narrow, and 

 closely arranged side by side. In this respect they come very near the 

 Constricted Worm {A. constricta, Rosa). The position of the first dorsal 

 pore has yet to be determined. In the Mucous Worm it can be readily 

 seen, not so here. 



The male pores are found on each side of the 15th segment, being easily 

 recognised in adult specimens by the small papillae upon which they are 

 seated. In some worms bearing a close relationship to this species, the 

 papillae are so large as to affect the two adjoining segments (14-16), but, 

 in this case, no such prominent position is held by them. The girdle is 

 conspicuous, dense, and closely fused on the dorsal surface, but each 

 segment is clearly defined beneath. It covers six to eight segments, two 

 only of which bear the tubercula piibcrtatis. The general outline of the 

 girdle ventrally closely resembles that of the nearly allied Mucous Worm 

 {A, mucosa, Eisen), as it is truthfully pourtrayed by Eisen in the plate 

 which accompanies his original description. 



One rather striking peculiarity may here be emphasized. In several 

 species of worms, such as the Brandling {A. fcetida, Sav.), the Long Worm 

 {A. longa, Ude), and the Common Earthworm {Ltinibricus terrestris, L.), we 

 find a tendency on the part of those segments which contain the sexual 

 organs to become tumid and pale on the ventral side. In this case, how- 

 ever, it is the dorsal surface which is so affected, especiall}- in segments 

 10 and II, and on the worm being dissected, the cause of this unusual 

 appearance is at once discovered. Whereas in most species of worms the 

 spermathecae are ventrally or laterally placed, in the Irish Worm they are 

 disposed on the back. 



I was fortunate enough to find eight specimens of this worm in the 

 batch consigned to me, and had recognised the novelty of the worm as 

 soon as the first specimen or two had been transferred to alcohol, so that 



