REPORT ON THE PYCNOGONIDA. 135 



In the first place, however, I wish to draw special attention to the fact that with regard 

 to Nymphon hrevicaudatmn, Miers, this rule admits of an exception. I examined a species 

 with large genital pores and swollen thighs, and provided with egg-masses on the ovi- 

 gerous legs. On investigating transverse sections of the thighs, I soon saw that this 

 specimen was a female. So far as I know, this is the first time that an exception to 

 this rule has been observed. In the second place, I wish in a few words to discuss 

 the circumstance that, although eight different species of the genus Colossendeis were 

 collected (together represented by thii"ty-one specimens, and four specimens of Colos- 

 sendeis proboscidea, Sab. (sp.), trawled north of Scotland during the cruise of the 

 " Knight Errant "), none of these are provided with eggs. The number of males, however, 

 is very restricted : there is only one male Colossendeis leptorhynchus among nine speci- 

 mens, there is one male Colossendeis gigas among six specimens, one male Colossendeis 

 megcdonyx among seven, and, finally, one male Colossendeis hrevipes. On the other hand 

 it is possible that the genus Colossendeis is an exception to the rule, and that the males 

 in this genus may not have the gallantry to nurse their babies as the males of the species 

 of other genera are accustomed to do. For, comparing the ovigerous legs of the males 

 with those of the females, a distinct difference is almost always easily observed : those of 

 the males are a great deal stouter, the fifth joint is as a rule swollen towards the 

 extremity, or furnished with a distinct knob, &c. ; but in the ovigerous legs of the 

 males of the species of Colossendeis, these differences in form and size are never observed. 

 So it is quite possible that they deal diff'erently with their eggs from the species of 

 other genera. 



The species provided with eggs are: Nymphon hamatum, Hoek ; N. longicoxa, Hoek ; 

 N. fuscum, Hoek ; N. brevicoUum, Hoek ; N. brachyrhynchus, Hoek ; N. brevicau- 

 datum, Miers ; and Ascorhynchus minutus, Hoek. Of the latter species there are in 

 all two specimens, and of these one bears eggs. But the development of these eggs is 

 in its last stage, so that I was only able to ascertain the form of the larvae. The eggs of 

 this species are extremely small, and at the same time numerous. 



It consequently happened that my embryological researches were limited to the genus 

 Nymphon ; in so far not unfavourable, as yet almost nothing has been published on the 

 embryology of this genus. 



Full-grown males of the genus Nymphon bear the eggs on the fourth and fifth joints 

 of the ovigerous leg, or only on the fifth joint ; the cvxrious foliaceous appendages occur 

 on the sixth to the tenth joints of the leg, and have nothing to do with the egg-bearing 

 function of the leg. Yet it is i^ossible that they may be of some use in seizing the eggs 

 when just laid, but, on the other hand it must be observed, that in the genera where 

 these apj)endages occur, the ovigerous legs of the females are furnished with them as 

 well as those of the males. 



The eggs are soldered together and form in the species of Nymphon I studied, and 



