172 THE VOYAGE OF H.M.S. CHALLENGER. 



flagello composita. Oculi disciformes. Pedes qnatuordecira : dvio eorum paria aiitica 

 chelis monodactylis complanatis, secundi paris multo majoribus. Stylorum abdo:uinalium 

 paria tria. Abdominis appendicula terminalis simplex, erecta verruciformis." 



Ou this genus Speuce Bate, B. M. Catal., p. 87, remarks, " Dana has arranged this genus in bis 

 subfamily Lysianassinaj. Not having seen a specimen, I adopt the same arrangement ; b\it 

 judging from the figure of the author, I should be inclined to classify it near to Nicea of 

 Nicolet, from which the female appears to differ only in the posterior pair of pleopoda 

 having two branches^a feature that the author has not alluded to in the description of the 

 animal, although exhibited in the figure. It is this character, together with the absence of 

 any mention whether the mandibles are furnished with an appendage or not, that has 

 lirecluded my placing it among the Orchestidae." 



Axel Boeck in 1870 united Allorchestes, Dana, and Nicea, Nicolet, as synonyms to Hijali', 

 Eathke. In this identification I myself (1876) and Wrzesniowski (1879) have agreed with 

 him. Faxon, Crustacea of the Lake Titicaca, 1876, takes a different view, which, to make 

 the subject intelligible, must be given in full. The genus Allorchestes, he says, " differs 

 from Nicea, Nicolet (as limited by Bate and Heller) in having the telson single instead of 

 double or cleft. The fourth segment of the palpus of the maxillipeds is well developed, as 

 in Nicea and Gammarus, and, as in these genera, is commonly unguiculiferous. Neither 

 Dana, in describing Allorchestes, nor Nicolet, in his description of Nicea, (published in tlie 

 same year), mentioned the form of the telson. The two names were therefore synonymes. 

 Bate, in a list of British Ain2)hipoda, published in 1856 in the Eeport of the British Association 

 for the Advancement of Science, indicates, without describing, two genera, Allorchestex, 

 Dana, and Galcmthis, gen. nov., which, as appear.? from his subsequent description, were 

 based upon the trivial character of a different length of the first and second antenn®, and a 

 differently formed telson, Dana's name, Allorchestes, being restricted to those species in which 

 the first antennae are (at least) as long as the peduncle of the second antennas and the telson 

 entire, and his own name Galcmthis including the species with the two pairs nf anteniife 

 subequal and short, and the telson cleft or double. In 1861 he suppressed the name 

 Galanthis in favor of Nicolet's Nicea. The proportion of the antennas and the form of the 

 telson brought together by Bate in his generic diagnoses are not in reality always con- 

 comitant, and Heller for the first time properly distinguished the two genera by the 

 character of the telson alone. Grube (1866) adopts the relative length of the two pair.s of 

 antennae (at most a sijecific character) as the generic distinction. All h.is species of Alhir- 

 chestes have a double telson, and should be transferred to Nicea. 



"Boeck (1872) apparently misled by the fact that Bate carelessly describes Kicea Nihsonii with 

 an entire telson, and places it under Allorchestes^, would unite the two genera, giving as a 

 generic character ' cqipendLc caudal is hrcvis, crassa et fissa.' He furthermore considers botli 

 Allorchestes and Nicea synonymous with Eathke's older Hijale, the type of which, //. pontica, 

 was carefully described and figured with the posterior caudal stylets two-branched. Boeck 

 has not had access to Eathke's type, as far as I can learn ; but in a specimen from the 

 Mediterranean 'which is doubtless Eathke's species,' he finds the last pair of saltatoiy 

 appendages one-branched. This assumption of identity, it seems to me, cannot outweigli 

 the careful description and illustration of the founder of the genus, unless confirmed by 

 examination of the type of Hijale Poidica. 



"In 1874 Professor S. I. Smith described a new amphipodous genus, Htjahlla, from the fresh 

 waters of the United States, diflering from 'Hijale' in having a styliform fifth segment to 

 the palpus of the maxillipeds and an entire telson. The so-called fifth segment muy 

 perhaps be more correctly regarded as a movable spine, like those seen both lateral and 

 terminal on the caudal stylets, or like the nnijuis which tips the dactylopodite of the 

 thoracic legs. However this may be, it is quite as well developed in several species of 



