300 The Irish Naturalist. 



furnished with toothed spines and present in both sexes, as 

 the typical form of the group. All these three pairs of limbs 

 in front of the four pairs of walking-legs are here present in 

 their highest state of perfection. From such a prototype the 

 other genera seem to have been produced by modification 

 — in most cases of a degenerative tendency. In the paper 

 already referred to, Prof. Schimkewitsch suggests how series 

 can be formed leading on to genera showing extreme con- 

 centration of the body and nervous system, or the reduction 

 or loss of one or more of the three front pairs of limbs. And 

 in Ta7iystyhim w^e find the concentration of the body carried 

 to the farthest possible point, while the chelifori have almost 

 vanished, and the palps have lost several of their joints. 

 Further, the beautiful denticulate spines, which in Ny??ipho7i 

 and other genera are to be found on the false legs, are here 

 replaced by simple spines (fig. 5). 



Our European species, Ta7iystylu?n conirostre, like the other 

 species of the genus, is of very small size, measuring only 

 I mm. in length (fig. i). It may be distinguished by the palps 

 possessing only four joints (fig. 4). Each of these limbs con- 

 tains an excretory gland, observed by Dr. Dohrn, which opens 

 towards the base of the second joint (fig 4, «). In the other 

 species the palps are six or seven-jointed, and Dr. Dohrn 

 states that traces of the vanished joints are sometimes to 

 be seen in Naples specimens of T. conirostre. Also it seems 

 that the degeneration of the chelifori has gone farther in T, 

 co7iirostre than in the other species. It is interesting to note 

 that in our Bundoran specimen these organs (fig. 2, «) are in 

 an extremely vestigial state, being decidedl}' smaller than in 

 examples of the species from Naples in the Dublin Museum 

 collections. The lateral processes of the Bundoran animal lack 

 the spines described and figured by Dr. Dohrn as occurring 

 there in his Mediterranean specimens. Such minor differences 

 will not, however, warrant the creation of a new specific 

 name. In the North American species, T. orbiculare, Wilson, 

 which ranges along the Atlantic coast from Martha's Vine- 

 yard as far south as Virginia, the chelifori are rather less 

 reduced, the palps are six-jointed, and the spines on the 

 false-legs are sometimes bifid. It will be remembered that 

 the type of the genus, T. styligeru77i, Miers, came from the 

 shores of Kerguelen, an island situated in latitude 49*^ S., 



