Miscellaneous. 100 



The adult male presents the pleon characteristic of the male of 

 Phryxas, without pleopoda or uropoda. But the atitenna^ and the 

 rostrum strongly remind us of the structure of the Cryptoniscian 

 embryos. 



The examination of Dajas renders that of Aspidophrums much 

 easier. The Aspidophryxus which has been entrusted to us by Jtlr. 

 Norman had been determined as A. peltatus by G. 0. Sars. But 

 the typo of Aspidopliryxus peltatus described and figured by Sars is 

 parasitic upon Erythrops Goesi, and what we know of the vigorous 

 specificity of the Epicarides to each definite host led us at once to 

 regard the parasite of Erythrops mlcrGphthalma as belonging to a 

 distinct species. A minute comparison of this parasite with the 

 figures given by G. 0. Sars, which are so exact, ajjpears to us to 

 justify this supposition, and we shall give the name of Aspido- 

 phryxus f<arsn to the Epicaride of Eryt]irop>s microphthalma . 



This new species differs from Aspidophryxas peltatus (1) in the 

 less widened and more slender general form of the female, (2) in 

 the number and arrangement of the ova in the incubatory chamber. 



While in A. peltatus the ova are diffused in great numbers and 

 without order in the incubatory cavity, in A. Sarsi they are 134 in 

 number, arranged in regular concentric rows, each row containing 

 respectively 17, 17, 15, 10, 5, and 3 ova in one half of the body, 

 between the free margin and the median line. These ova are more- 

 over larger than those of A. peltatus. Further, the animal is less 

 distinctly segmented. In the male, on the contrary, the segments 

 of the pleon, although soldered together, are more distinct than in 

 A. peltatus 



If we referred exclusively to the description and figures given by 

 G. 0. Sars, there would be much more considerable differences 

 between the two species, and the genus Aspiduphryxus would seem 

 far removed from the genus Dajus. The complete absence of incu- 

 batory lameUoe in the female {lamime incuhatorice nulla') and the 

 existence of only six pairs of thoracic feet in the male would con- 

 stitute characters of great importance in this group of Epicarides. 

 But we have ascertained that these characters were due to errors of 

 observation. The incubatory lamellae all exist as in Dajus ; the 

 first four pairs are more reduced, in consequence of the api)roxima- 

 tion of the thoracic feet to the anterior part of the body. Like the 

 first pair in the other Bopyrians, they have only an accessory func- 

 tion in the protection of the ova. As to the fifth lamellae, these are 

 represented by a pair of narrow plates bordering the free edges of 

 the greatly enlarged last thoracic somites ; they terminate in digi- 

 tations posteriorly. These plates are applied to each other exactly 

 in the median line, and with the lateral ventral folds of the thoracic 

 somites form the incubatory cavity properly so called. 



The pleon also presents considerable reductions compared with 

 that of Dajus. It is completely destitute of appendages and forms 

 a small cavity, in which is lodged the male, folded up like a Scara- 

 baean larva and placed in profile. 



This male differs little from that of Dajus ; the segments of 



