720 RECORD OF CURRENT RESEARCHES RELATING TO 



first habitation, which liacl been preserved in sjiirit ; in a few minxitcs 

 the calm crustacean was quite at ease. 



Observations with Ptcrotrachea only led to negative results ; as to 

 the males, the greater number were found not to inhabit such 

 " houses," and in the case of PhronimeUa, no male was observed in 

 one ; while as to those of the female, not only were they excessively 

 thin, but as chemical observation never revealed the presence in 

 them of the cellulose, which is so characteristic of the integument of 

 the Tunicata, it may be concluded that whatever the houses of species 

 of this genus are formed from, they are not made at the expense of 

 any of these animals. 



Some young Stages of Penseus Caramote.* — Mayer's next note 

 deals with some forms which he found in the central canal of Pyro- 

 soma elegans. The points said by Heller to be characteristic of the 

 species are: — (1) The deep longitudinal rostral groove; (2) The 

 shortness of the terminal filaments of the superior antenna) ; and (3) 

 The projections on the lateral surfaces of the sixth abdominal seg- 

 ment. As to the third point, the projections were not visible in the 

 young, inhabiting Pyrosoma, or in the smaller free-living forms. The 

 first was only visible when the animal left its home, and in the 

 youngest stages the antennary filaments are as long as the lamellar 

 appendages of the inferior antennae. In the earliest stages it is 

 impossible to distinguish the sexes by any differences in the characters 

 of their appendages, but in specimens 60 mm. long the internal 

 branches of the first abdominal foot are closely applied to one 

 another, although it is not till later that they fuse into an unpaired 

 organ. 



Hermaphroditism of the Isopoda.t— To English readers this is 

 an especially interesting subject, as the results of Mr. BuUar of Cam- 

 bridge, were, when published, traversed by Mr. Moscley, who had at 

 the same time to deal with Captain Hutton of New Zealand, who had 

 asserted that Pcrqyatus, which, on account of his very notable dis- 

 coveries, might be almost called Mr. Moseley's especial property, was 

 likewise hermaphrodite. | Paul Mayer now states that the results of 

 his predecessor (Bullar) were quite correct, and that therefore there 

 really does exist a group of hermaphrodite parasitic Isopoda. The 

 basis for these results are the observations which he has been able to 

 make at Naples on Cymothoa, Anilocra, and Nerocila. 



The free-living Isopoda are provided with three pairs of testes, 

 which are placed one behind the other, and open to the exterior by a 

 common vas deferens placed in the seventh thoracic segment ; in 

 addition to this there are two or (Oniscidte) one penis. The female 

 is provided with an elongated ovary and short oviduct, which opens 

 on the fifth thoracic segment. Now in the adult Cymothoa what 

 we find is this : the ovaries, which are attached posteriorly and 

 anteriorly to the dorsal wall, take a longitudinal direction ; the 



* ' Mitth. Zool. Stat. Neapel,' i. (1878) p. 4i). 

 t Ibid., i. (1879) p. 165. 



X Captain Hiitton has since allowed the existence of male spceimeus of 

 Peripatus (cf. s. v. Peripatus, ' Zool. Record' for 1877). 



