ADAM WHITE 197 



the great size of two feet in length, with a carapace more 

 than twenty-one inches in circumference. Already in 1883, 

 Mr. T. Jeffrey Parker, P.R.S., had proposed a new sub- 

 genus Jasus for those species of Palinurus which have the 

 rostral character assigned to Palinosytus and which have 

 no stridulating organ. He therefore claims that the name 

 Jasus should supersede Palinosytus. 



Idnupdris, White, 1847, has the rostrum dilated, bi- 

 partite, with the processes flat, and the anterior margin 

 spinulose. To this genus belongs Idnuparis trigonus (de 

 Haan). 



Panulirus, White, 1,847, contains the numerous Eastern 

 and one or two Western species, in which there is no central 

 rostriform tooth, which have the ocular segment exposed 

 and membranous, the flagella of the first antennse long and 

 slender, and their segment produced considerably in ad- 

 vance of the frontal margin, that being generally armed 

 with strong teeth. Panulirus penicillatus (Olivier) has 

 already been mentioned as having exhibited the singular 

 monstrosity of an eye-stalk developing a flagellum or lash- 

 like termination. In this species Spence Bate enumerates 

 twenty-six pairs of branchiae, this number including six 

 pairs of ' mastigobranchise,' which are in fact epipods, 

 whether accompanied or not by podobranchiae, which also 

 arise from the first joint. With the help of Mr. R. I. 

 Pocock, I have come to the conclusion that Imiuparis and 

 Panulirus were not named as generally supposed by Dr. J. E. 

 Gray, but by Mr. Adam White, in 1847, the characters of 

 the new genera being left to be inferred from those of the 

 known species which were transferred to them, a slovenly 

 method of definition which is much to be deprecated. 



Palinurellus, von Martens, 1878, is distinguished from 

 Palinurus, by the feeble antennae, the nearly smooth cara- 

 pace, and its rostriform front covering the base of the 

 antennffl and eye-stalks. The type Palinurellus gundlachi 

 is from Cuba. The genus Synaxes, which Spence Bate 

 established in 1881, and retained in 1888, is described as 

 having the rostrum produced beyond the segment of the 

 first antennae and united with that of the second antennas 



