THE ANNALS 



AND 



MAGAZINE OF NATURAL HISTORY. 



[THIRD SERIES.] 

 No. 9. SEPTExMBER 1858. 



XVI. — On Praniza and Anceus, and their Affinity to each other. 

 By C. Spence Bate, F.L.S. &c. 



[With two Plates.] 



The small Crustacea knowTi by the names of Anceus and Praniza 

 have long been objects of interest to naturalists. The peculiarity 

 of their form and our ignorance of their habits have not only in- 

 duced carcinologists to consider them as forming distinct genera, 

 but even to group them in separate families. 



Colonel Montagu described the first specimens in the seventh 

 and eleventh volumes of the Linnaan Transactions, among other 

 marine animals taken on the coast of South Devon. Dr. Leach 

 believed that they might ultimately be found to be but different 

 sexes of the same species, and this has been the opinion of many 

 other naturalists. 



There has been a mystery attendant upon their habits also. 

 Praniza has frequently been taken associated with parasitic Crus- 

 tacea : not so Anceus. Hence Colonel ^Montagu, Mr. Westwood, 

 and M. Otto have considered Praniza to be a parasite upon certain 

 animals. It has been taken, by Colonel Montagu, attached to the 

 Father Lasher {Coitus Scorpius). On the other hand, it lias been 

 found quite as frequently, along with Anceus and other non- 

 parasitic Crustacea, in the crevices of rocks and in shore-pools, 

 as well as in deeper water. In the first of these positions it 

 has been taken on the clayey shores of Strangford Loch by 

 Mr. Ilaliday, who, I believe, is among those who iiold most 

 strongly the opinion that it is a separate species of animal from 

 Anceus, his conclusion being based upon the structure of the 

 oral organs. Here hyj)otheses have rested, until facts of greater 

 or less importance should assist us in arriving at a correct con- 

 clusion. 



On the 26th of November, 1856, a paper by M. Hesse of 

 Brest was read by M. Costc before the Academy of Paris, in 



Ann. if Mag. N. Hist. Ser. 3. Vol. ii. 12 



