BY DAVID G. STEAD. 753 



fourth the length of the following and terminal portion which is 

 long, styliform, and tapers to a very fine point, perforated by the 

 ejaculatory duct. The long terminal joint is supplied with short, 

 almost spiniform, recurved hairs in the adult male. These would, 

 perhaps, assist the animal to keep the organs in position during 

 copulation. As compared with the first those forming the 

 second pair of pleopoda (Fig. 3, D) are rather insignificant.* In 

 conformation they are somewhat similar to the former, but are 

 more lamellate. In adult males, the end of the last joint is 

 always found inserted into the base of the terminal joint of the 

 first pleopod. 



The female pleon, which, comparatively, is by far the largest, 

 consists of the full number of segments, all of which are movable 

 upon one another. It is fringed with short setie, and is capable 

 of such extension as to be almost in line with the carapace. The 

 sternal aspect is chiefly membranous, but is calcified in the central 

 portions of each of the second, third, and fourth somites, so as to 

 give support to the large appendages (pleopoda) to which the ova 

 are attached. In this sex, the ver}^ lai'ge ovate openings of the 

 oviducts are situated on the sixth thoracic segment at the base of 

 the third pair of pereiopoda, but nearer to the mesial longitudinal 

 line. 



Each pleopod consists of a small protopodite, from which depends 

 a terminal biramous portion (endopodite and exopodite). The endo- 

 podite is rather flat, 2-jointed, and is clothed with beautifully fine, 

 long, yellowish, silk)'^ hairs. These are distributed in great 

 number over the two edges, and posterior aspect only of the 

 endopodite, the anterior aspect being quite free and smooth. The 

 posterior face is ribbed, and between the ribs the hairs are attached 

 in regular lines. To these hairs the minute ova ai^e attached by 

 a gummy secretion forming a pedicle. The length of this pedicle 

 is variable, usually wide and short, about same length as diameter 

 of ovum, but is sometimes long and narrow. The ova, which are 



* This cannot be said of all the Brachyura, as in some {Cancer) the 

 second pair of pleopoda is the longer. 



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