86 REPORT — 1887. 



third fine form which appears to be altogether new and belonging to a 

 genus allied to the last. The Ergasdciis, I may mention, was also taken 

 by the ' Porcupine ' Expedition off the Spanish coast ; and of the Hete- 

 rocnjpta I possess specimens given me previously by the Marquis de 

 Folin, which were taken by the ' Travailleur ' Expedition in the Fosse 

 de Cap Breton. 



With this brief review of the more interesting Brachyura, J must 

 pass by the remaining groups and only notice one remarkable crustacean 

 of excessive interest. My friend, Professor Sars, to whom I sent a 

 specimen, writes to me on it : ' The interesting parasite detected by you at 

 K^aples is certainly a highly remarkable and perplexing form, and the 

 discovery of this animal would alone, I believe, fully recompense your 

 voyage to Italy.' 



In 1882 a memoir on an extraordinary parasitic crustacean discovered 

 by Professor Lacaze-Duthiers was published by the Institut de France, 

 illustrated with eight quarto plates. 



The parasite thus described, Laura Gerardice, Lacaze-Duthiers, lives 

 in one of the Antipatharian Actinozoa, which was made the type of a 

 genus by Lacaze-Duthiers, Gerardia LamarcH, S?i\me; and that author 

 regarded the parasite found by him as an aberrant member of the 

 Cirripedia, and constituted a new section to receive it, named Ascotho- 

 r acid a. 



It is to this genus that the form now discovered appears to have closer 

 relationship than to any other. The Neapolitan parasite, for which I 

 propose the name Synagoga^ mira, is also a parasite on an Antipatharian, 

 AntipatJies larix, Ellis, but while Laura, is buried beneath the tissues of 

 the host, being completely covered, except in one minute spot by the 

 sarcosome of Gerardia, Synagoga is an external parasite attached to the 

 surface of the Antipathes. At first sight the latter looks veiy unlike the 

 former, and, with the naked eye might easily be mistaken for one of the 

 Cypridinidae, inasmuch as the body of the animal is covered by two nearly 

 circular valves ; these valves (' carapace,' Lacaze-Duthiers) are in Laura 

 of enormous size and three times the length of the body, but in Synagoga 

 they are shorter than the body. In Laura the antenna are weak, feeble 

 structures ; here they are strongly developed grasping organs ; the mouth 

 organs in both cases are formed for piercing and sucking, and follow the 

 same type. In both genera the adductor muscle which passes through 

 the body into the valves is similar; and in both, as in the Ostracoda, 

 the organs of reproduction are extended on either side into and beneath 

 the valves. Both genera are furnished with six pairs of limbs posterior 

 to the oral members and a caudal bifurcation ; but while in Laura these 

 members are simple, apparently unjointed, and somewhat rudimentary, in 

 Synagoga they are two branded, jointed, and freely setose, and the laminae 

 of the caudal furca are much longer, spiued on the edges, and provided 

 with long setae. It will thus be obvious that Synagoga is a type of much 

 less retrograde character than Laiira. Upon its relations I will only say 

 at present that while, on the one hand, there is much in its structure 

 which reminds us of the Cypris-condition of a larval Cirriped, there are 

 also features which recall strongly to us the much disputed genus Nehalia. 



' iviuywyi], a meeting-spot. 



