186 bulletin: museum of comparative zoology. 



tubercles of the trunk segments and of the lateral processes are very much less 

 pronounced, and the animals are rather less spinous throughout. Thus the 

 proximal joints of the palp are practically smooth, and the stiff spines on the fifth 

 joint described and figured by Schimkewitsch (1893, pi. 2, fig. 12) appear to be 

 lacking entirely. The ovigers are considerably shorter in proportion, while the 

 bristles forming a tuft at the end of joint 6 are only about half as long as joint 7 

 instead of equalling that joint as they do in the male. Through the kindness of 

 the authorities of the United States National Museum I have had opportunity to 

 examine the specimens described by Schimkewitsch, and I find that this latter dif- 

 ference holds in the case of the female of that lot. Otherwise the ovigers of the 

 two sexes are nearly alike. 



The eye tubercle is lower and less pointed in the specimens collected in 1904. 



There are two or three discrepancies in Schimkewitsch's description, as when he 

 states in speaking of the joints of the leg (loc. cit., p. 3S), " le quatrieme est uue 

 fois et demie plus long que le second." His own figure (pi. 1, tig. 4) as well as 

 both lots of specimens I have examined show it to be fully twice as long. Again, 

 on the same page, he arranges the third joint as intermediate in length between 

 the fifth and sixth, which is obviously a mistake. He gives the arrangement of 

 the joints of the leg, going from longer to shorter, as follows : 4, 5, 3, 6, 2, 7, 8, 1 ; 

 the series should read, 4, 5, 6, 2, 8, 7, 1, 3. Joints 7, 1 and 3 may be nearly 

 of the same length, but that joint 8 is longer than joint 7 is shown in Schimke- 

 witsch's own figure (1893, pi. 2, fig. 16). 



As will be observed from what has been said above, the two specimens collected 

 by the Eastern Tropical Pacific Expedition, differ from those described by Schimke- 

 witsch principally in the smaller size, the decidedly less developed dorsal protuber- 

 ances, and the less pronounced spinosity of the palps. I cannot but believe, 

 nevertheless, that they merely represent probably younger individuals of the same 

 species, though they possess the adult characters of having the chelifori not 

 distinctly chelate (the condition is shown in pi. 3, fig. 6), which is usually a char- 

 acteristic of the young in this genus, and the genital openings * are plainly dis- 

 tinguishable in the usual position on all four pairs of legs. It is to be noted, 

 however, that these specimens came from much shoaler water than those examined 

 by Schimkewitsch (556 fms. and 774 fms. as compared with 1270 fms. and 1573 

 fms.), and it is possible that they may represent a shoaler-water type or subspecies. 

 I do not care, however, to name it as such on the insufficient material at hand. 



Ascorhytichus agassizii is certainly very close to A. glaber Hoek in general 

 appearance and proportions, and if they came from less widely separated localities 

 I do not think I should hesitate, from the descriptions, in considering them the 



1 It is usual in this genus for the genital openings to occur on all four pairs of 

 the legs in the female, and only on the third and fourth pairs in the male. Upon care- 

 ful examination, however, of two of the males taken in 1891 and reported on by 

 Schimkewitsch (1893), I discovered that in one of these there is an additional genital 

 opening situated on the second leg of the right side. No corresponding opening 

 could be detected on the left side. 



