20 THE VOYAGE OF H.M.S. CHALLENGER. 



species, not to speak of its much smaller size, by the smooth and almost globular carapace, 

 the shorter pseudorostral projection, and the simple structure of the caudal segments. 



Description. — I have only had a single specimen of this species for examination, a 

 full-grown female with greatly developed marsupial pouch. Its length does not exceed 

 3tj mm., and it thus belongs to the smaller forms of this order. The form of the body 

 (see figs. 21, 22) is that characteristic of the genus, the anterior part being greatly dilated 

 and almost globular, whereas the posterior part is extremely slender. 



The carapace is very large and cpiite smooth at the sides, about as thick as high, and 

 with the dorsal line evenly arched. The pseudorostral projection is short and obtuse, and 

 limited below at each side by a well-marked notch. The ocular lobe (fig. 23) is rather 

 shorter than in the preceding species, and is provided at the somewhat dilated extremity 

 with distinctly developed visual elements. 



The four exposed segments of the trunk decrease rapidly in size, and the two posterior 

 do not exceed the caudal segments in height or thickness. 



The tail is very slender, cylindrical, and somewhat longer than the anterior division 

 of the body. It has a slight keel running along the middle of the dorsal surface, and this 

 keel is also continued along the segments of the trunk and the carapace ; but for the rest 

 the segments are quite smooth and exhibit the usual relation in length. 



The colour of the animal is whitish, with small patches of brownish-pink, especially 

 along the sides of the anterior part of the body. 



As to the limbs, they on the whole seem to agree fairly well with those of the 

 preceding species. The three anterior pairs of legs were, however, partly broken in the 

 specimen examined, and it may be that the terminal part of the first and second pairs 

 might have exhibited some minor differences, as to the relative length of the several 

 joints. 



The marsupial pouch is greatly developed and projecting below, giving the anterior 

 part of the body an almost completely globular form. 



Habitat. — I found the above-described specimen among some dredged sand kindly 

 sent to me by Mr. John Murray. The sand was procured with the dredge on September 

 8, 1874, at Flinders Passage (between Australia and New Guinea), from a depth of 

 7 fathoms. 



3. Cyclaspis exsculpta, n. sp. (PL I. figs. 24-26). 



Specific Characters. — ?. Carapace very gibbous and strongly sculptured by elevated 

 crests limiting irregular depressed areas ; two of the crests exceedingly strong, crossing 

 the dorsal surface of the carapace transversely, and uniting on each side near the infero- 

 posterior angle, being moreover connected above on each side by a thin longitudinal ridge, 

 whereby a large depressed area of irregularly oval shape is formed on each side of the 



