ZOOLOGY AND BOTANY, MICROSCOPYj ETC. 513 



On a specimen of Asjndophryxus peltatus the authors have found the 

 females and two males of a very singular Coi^epocl, which they call 

 Aspidoecia Nurmani. The female has the form of a miniature Sacculina ; 

 it is fixed to the Mysis on which tlie Aspidopliryxus is parasitic by a 

 short peduncle, which ends in a sucker, and to the parasite by an 

 elongated cord ; on this cord the male was found. Towards the free 

 end of the body were two ovigerous sacs, containing eight to ten 

 segmenting eggs. The males have a form somewhat similar to that of 

 the males of Sphseronella Lenckarti ; they are fixed by a spiral chitinous 

 filament secreted by cement-glands, and a large sucker allows the 

 jiarasite to apply its oral apparatus to its host. At the hinder end of 

 the body are two lateral lobes which contain the spermatophoral sacs. 

 This new genus appears to be closely allied to the Choniostoma mirahile 

 lately discovered by Hansen, and, with Spliaeronella, should be placed in 

 the aberrant family of the Choniostomatidge. 



Morphology and Systematic Position of the Dajidae.* — MM. A. 

 Giard and J. Bonnier offer additional evidence in support of their view 

 tliat the Dajidas are intermediate between the Cryptoniscina and the 

 Bopyrina. Dajus mysidis has five pairs of apiieudages, and the fifth 

 pair, which escaped the notice of Gerstaecker, are the best developed and 

 form the greater part of the incubatory cavity. The morphology of the 

 head and thorax differs little from that of the similar parts in the 

 Phryxina. The adult male presents the pleon which is characteristic 

 of Phryxiis, but the antennae and rostrum forcibly recall the structure of 

 embryonic Cryptoniscina. 



The study of Dajus simplifies that of Aspidophryxus ; the species lent 

 to the authors by Dr. Norman had been determined as A. peltatus by 

 G. O. Sars ; but it appears to be distinct from that species and may be 

 called A. Sarsi ; the difi'erences between the two species are minutely 

 pointed out. Certain errors in Sars's original description are so noted, 

 and the correction of them shows that Aspidophryxus is more closely 

 allied to Dajus than could previously have been imagined. 



Tegumentary Coverings of Anatifer and Pollicipes.j — M. E. Koehler 

 points out that the characteristic tegumentary coverings of Pollicipes 

 have a very complicated structure, and do not at all merit the name of 

 scales. The chitinous layer of the peduncle has on its surface a series 

 of conical depressions, clothed by a membrane which is continuous with 

 the general cuticle which covers the chitinous layer. This membrane 

 does not, however, stoj} at the edge of the j^it ; it is prolonged freely, 

 and forms a kind of cupola, the internal region of which is placed in the 

 layer of chitin and exhibits very elegant longitudinal and transverse 

 striae, while the outer half has a uniform dark-brown coloration. The 

 internal region contains a rounded concretion which effervesces with 

 acids. The external region is occupied by a whitish mass which com- 

 pletely fills the cavity of the cupola ; it is limited internally by a very 

 line membrane, which fuses with the cuticular layer. It is the whitish 

 mass which gives the white colour to these so-called scales, while their 

 edges are nothing else than the external borders of the cupola. At the 

 base of each cupola there is a rounded orifice which is bounded by a 

 slightly swollen edge ; the edges are continuous with a tube, the wall of 



* Comptes Kendus, cviii. (1889) pp. 10^0-2. f T. c, pp. 755-7, 



