THE OBJECT OF LARGE OVA 177 



closely allied species. In 1882 he had explained that 

 Bell's Munida Rondeletii was distinguished from the other 

 species by its very small eyes, not furnished with a circlet 

 of hairs, and by the complete want of the two dorsal 

 spines on the third pleon-segment. But Bell gives an- 

 other specific character, ' second and third segments of the 

 abdomen, the former with six, the latter with four small 

 spines on the anterior margin ; the other segments with- 

 out spines.' In two specimens from the Clyde, both having 

 circlets of hairs to the eyes, the pleon has on successive 

 segments, in one case, six, four, and two spines, but in the 

 other six and four and none. 



Grimotheaj Leach, 1820, established to receive the 

 Galathea gregaria of Fabricius, is still in an uncertain 

 position, it being supposed by some that the species is a 

 young form of Munida subrugosa, Dana. 



Munidopsis, Whiteaves, 1874, has eyes devoid of pig- 

 ment, and the stalk of the eye frequently prolonged beyond 

 the cornea in the form of a spine or spines. The species 

 are found in depths varying from 100 to more than 2,000 

 fathoms. ' It is probable,' Dr. Henderson remarks, ' that 

 the loss of sight is compensated by a greater development 

 of the tactile sense, and in some species this is evidenced 

 by the great length of the antennal flagella, which in all 

 probability enable the animal to grope its way about on 

 the bottom.' The eggs are few and large, as is often 

 the case with the ova of deep-water species, which are 

 supposed to find their advantage in passing through 

 several of their metamorphoses within the egg, so that 

 the- young one is hatched in a form nearly like that of the 

 parent. 



Eumunida, S. I. Smith, 1883, occupies an exceptional 

 position, for the peduncle of the second antennas has five 

 distinct joints, the third maxillipeds are without the usual 

 two pairs of rudimentary arthrobranchise, and the pleon 

 of the male is without appendages on the first five seg- 

 ments. The type species, Eumunida picta, Smith, was 

 taken in the North Atlantic. 



Uroptycfuus, Henderson, 1888, is the equivalent of 



N 



