HEEMIONB HYSTRIX. 267 



The second foot has dorsally a tuft of pinnately spinous bristles as in the other 

 members of the group, for instance, A. aculeata, — little variation occurring in the species. 

 In the ventral branch are two bristles (Plate XXXVII, figs. 6 and 7), an upper with 

 a strongly spinose edge above the powerful tooth, and a lower with indications of four 

 spines, viz. the usual powerful inferior one, the somewhat less spine above it, and 

 indications of two others beyond, the last being slightly developed. The foot has 

 numerous globular papillae on its surface. 



The third foot, which carries a cirrus, has dorsally and internally a series of 

 powerful bristles minutely nodular (Plate XXXVI, fig. 9), and with a well-marked curve, 

 while externally a group of smaller forms of a similar kind occurs. This nodular 

 development on the surface is peculiar, and forms a swelling below the tip as 

 if it were a secondary development. The prominent granules or minute nodules 

 are not affected by potash. The ventral division has often stout bristles with the 

 spinose tips above the powerful fang, as shown in Plate XXXVII, figs. 6 and 7 before 

 mentioned; but in some the spines above the fang are only four in number, while 

 in others they are eleven. At the ventral edge of this division of the foot are 

 numerous pinnately spinous bristles, as indicated in the dorsal division of the second 

 foot. 



In the fourth (a scale-bearing foot) the dorsal bristles are still curved, and occa- 

 sionally minutely nodular, but much longer than in the third, and the tips of some are 

 shaped as in the hooked forms. A few shorter and straighter spines occur externally. 

 Ventrally the powerful bristles still show spinose tips, but the spines above the inferior 

 fang are diminishing in number, one having only two. 



The fifth (likewise a scale-bearing foot) has dorsally the somewhat broad, granular 

 bristles, the tips of the amber-coloured ventral still having spines, the number of the 

 latter above the great fang from above downwards in the three bristles present in the 

 example being two, three, five. 



The sixth foot (cirrus-bearing) has dorsally short, curved, and slightly granular 

 flattened bristles dorsally and internally ; externally a shorter and more slender form of 

 similar character. Ventrally three bristles occur, with two, two, and three spines above 

 the great fang. 



The seventh foot has numerous curved, granular bristles dorsally, besides the spines, 

 some with greatly elongated tips, which, moreover, are somewhat hastate. On the 

 ventral bristles only two spines in all are present above the fang. 



In the eighth foot (cirrus-bearing) the dorsal bristles are curved and granular, with 

 a tuft of longer and more slender bristles to the exterior (below the cirrus). The three 

 ventral bristles had each two spines above the fang. The segmental (nephridial) papilla 

 begins on the posterior border of this foot, completely hidden in the fissure between it 

 and the next foot. 



Dorsally in the ninth foot were numerous curved granular bristles with somewhat 

 blunt tips. Beyond these stretch the long characteristic brown spines with the glochidi- 

 ate tips. Ventrally the three bristles have from above downwards one spine above the 

 fang, two and one. Their shafts are strongly grooved. 



The tenth (a cirrus-bearing foot) has dorsally the shorter curved granular spines, 



