328 DISCOVERY REPORTS 



It consists, as may be seen from the figure, of a reticulum of connective tissue strands 

 (Fig. 9, c.t.) in some nodes of which are lodged its nuclei. The chromatin content of 

 these differs from that of adjacent nuclei. The chromatin is sparse and disposed within 

 the nuclear membrane as a thready reticulation. The connective tissue reticulum lies 

 between the integument of the limb (Fig. 9, chit.) and one of the muscles of the pleopod 

 (Fig. 9, pl.m.), and is bathed by the body fluid in the haemocoeUc space of the limb 

 (Fig. 9, haem.). 



The only other feature of interest in this simple structure is to be found in the 

 arrangement of the nuclei of the chitogenous epithelium in its neighbourhood. These 

 nuclei (Fig. 9, n.chit.ep.), which exhibit a central chromatin mass with radiating strands, 

 are fairly uniformly distributed beneath the integument except in the neighbourhood of 

 the connective tissue structure, where they are larger and are closely crowded. It must 

 be admitted, however, that other areas are to be found on the limbs, remote from the 

 structure under discussion, where the nuclei are rather irregularly crowded. I am 

 inclined to believe that the crowding of the nuclei shown in Fig. 9 has no relation, 

 therefore, to the network of connective tissue beneath them. 



Whether the organ described above is a photophore I must leave entirely in doubt. 

 There is no nerve supply and no chitinous lens associated with it, and its appearance 

 in section is not instructive, there being no resemblance to any other photophore 

 studied in the course of this work. 



V. CARIDEA: HOPLOPHORIDAE 



I. THE PHOTOPHORES OF HOPLOPHORUS NOVAE-ZEALANDIAE DE MAN, 

 H. TYPUS A. MILNE-EDWARDS, AND H. GRIMALDII C0UTI£RE 



Photophores appear to have been first described in a species of Hoplophorus by 

 Coutiere (1905, p. 3) when he published a description of a new species which he named 

 H. grimaldii. He mentions them as occurring on a number of the thoracic limbs, as a 

 long transverse streak at the base of the fifth thoracic limb, as a series of five to six 

 organs on the carapace and as lenticular bodies on the basal joints of the pleopods and 

 uropods. No description is given of the structure of these organs. Kemp (1910^, 

 p. 646), after describing the photophores of Systellaspis (as Acanthephyra) debilis, remarks 

 that the photophores of Hoplophorus grimaldii do not differ from them in any essential 

 feature, and that they occur in the usual positions on the pleopods and uropods, and 

 behind the bases of the last pair of legs. No mention is made in this work of the 

 structure of the photophores borne on the carapace, the first observations on which 

 appear to have been made by Dr Kemp in his notes made in the ' Discovery', in which 

 he refers to the presence in H. grimaldii of " four very small circular organs arranged in 

 a curved row near the lower border of the carapace and one other, immediately behind 

 the eye and situated about one-third the length of the carapace from the anterior 

 margin". Similar organs have also been observed by Dr Kemp in H. novae-zealandiae 

 and by me in H. typiis. 



