260 8. I. /Smith — Early Stages of the American Lobster. 



side, and the distal three all round, with slender spines. The propo- 

 dus (plate XVII, fig. 9) is the longest and slightly the stoutest of the 

 segments, the basal portion as long as the merus, the digital portion 

 much shorter than the dactylus and tapering rapidly to a short spine- 

 like tip, the inferior side armed -with several pairs of slender spines, 

 some of which are armed Avith two rows of acute teeth, and the distal 

 end, on each side at the base of the digital jjortion, with a long slen- 

 der spine armed, like those just mentioned, with two rows of acute 

 teeth. The dactylus itself is much shorter than the basal portion of 

 the propodus, tapers rapidly to the tip, which is terminated by a 

 spine nearly as long as the dactylus itself, and is armed on both mar- 

 gins with several small and slender spines. The exopodus (plate 

 XIV, fig. D, a) is just like the exognathus of the external maxillipeds, 

 except that the flagelliform portion is a little longer and comjjosed 

 of ten segments. The epignathus (fig. Z>, /;) and the thi-ee branchial 

 appendages (fig. X>, c) are almost exactly like those of the external 

 maxillipeds. In the specimen figured all the branchial appendages 

 were farther developed than in most of the specimens examined. 



The second pair of legs (plate XVII, figs. 1 and la, enlarged 20 

 diameters) are nearly or quite as long as and very much like the first 

 pair, but the endopodi are considerably more slender, the propodus is 

 scarcely stouter than the carpus, is armed with fewer spines beneath, 

 and the digital portion is much less developed, while the dactylus is 

 more slender and is terminated by a longer spine. The exopodus, 

 epipodus, and the four branchial appendages are just like the corres- 

 ponding parts of the anterior legs, the flagelliform portion of the 

 exopodus being composed of ten segments, as in all the other legs. 



The third pair of legs are in all respects like the second pair, and 

 appear to be quite indistinguishable from them. 



The fourth and fifth pairs of legs are styliform, a little more slender 

 than the second and third pairs, and the endopodi and exopodi in 

 both pairs are quite similar in structure. The endopodi of the fourth 

 ])air are armed with slender spines like those upon the second and 

 third pairs ; their propodal segments ai'e slender, longer than the 

 other segments, and are armed on the inside, near the base of the 

 dactylus, with several long spines themselves armed with two rows of 

 acute teeth ; and the dactyli are slender, rapidly tapering, half as 

 long as the propodi, and are each terminated by a slender, slightly 

 curved, spiniform stylet fully twice as long as the segment itself, and 

 armed upon the outer side with rows of acute teeth like those 

 upon the long spines of the propodus. The exopodi, epipodi, and the 



