1908.] GENUS OF AMPHIPOD CRUSTACEA. 371 



by the strong claws of the first gnathopods. The figure given is 

 that of a female, 25 mm. in length. 



In 1860, Axel Boeck published his ' Observations on the Nor- 

 wegian Amphipoda ' (3). In this work he added a new tribe to 

 the three already established primary divisions of the Amphipoda. 



This tribe, Prostomatce, was created for the reception of a " new 

 and remarkable form,'"' Trisckizostoma, which Boeck regarded as 

 a ti-ansition between the Hyperidse and Gammaridse, resembling 

 the former in the structure of the head, the eyes, the antennae, 

 and the abdomen, and having much in common with the Gam- 

 maridfe, especially with the family Orchestidas, and the genera 

 Ojiis and Anonyrc. 



The Frostomatce contain only the one genus Trischizostoma (so 

 named by Esmark, who first distinguished it, from the trifid tube 

 formed by its mouth organs) with the type species T. raschii, in 

 describing which Boeck specially notes the peculiar structure of 

 the first gnathopods. 



The specimens described by Boeck, tiiree large females, were 

 dredged by Prof. Rasch at " Havbroen," a bank 20 miles off the 

 west coast of Norway, in 100 fathoms. 



In 1862, Spence Bate in his British Museum Catalogue (4) 

 ■described and figured Guerinia 7iicceensis, placing the genus 

 Guerinia in the subfamily Phoxides of the Gammaridas, between 

 the genera Lafijstius and Lejndactylis. He adds, " For the 

 description of this animal I am dependent upon the accuracy of 

 the Rev. Mr. Hope's figure in the pamphlet quoted (Three New 

 Crustacea, Fauna of Naples) " ; but both the description and the 

 figures, though evidently copied from Costa's, are inaccurate and 

 misleading. For instance, in describing the second gnathopod, 

 Costa states that it has one joint less than the normal number, 

 being " entirely without a nail," and further, that "the fifth and 

 last (article), which represents the hand, is the shortest of all, com- 

 pressed, nnrrow at the base, dilated inferiorly, Avhere it is fringed 

 with stifii" hairs which increase in length towards the anterior 

 angle, the longest being twice the length of the hand " *. Spence 

 Bate gives the normal number of joints, applying Costa's descrip- 

 tion of the hand (propodos) to the nail (dactylos) thvis— " pro- 

 podos very small : dactylos triangular, dilated, compressed, 

 flattened at the apex, fringed with long hairs." In order to bring 

 the figure into agreement with his description he has emphasised 

 the line by which Costa indicated the articulation of the last 

 joint, so making it appear as another very small joint and calling 

 it the " propodos." 



In 1865, Lilljeborg(5) published two papers on the Lysianassina, 

 the " Lysianassa magellanica etc." in English, and the " Bidrag 

 till Kannedomen " in Swedish. They contain practically the same 



* "II quinto ed ultimo (articolo) clie rappresenta la mano e il piu corto di tutti, 

 compresso, stretto alia base, dilatato iiiferiormente, ove e ornato di peli rigidi e 

 crescenti in lunghezza verso I'angolo anteriore, i maggiori esseudo luiighi il doppio 

 della lunghezza della mano." 



