12 PACIFIC NATURALIST VOL. I, No. 3-4 Miller, R. C. 1924. Wood-boring Crustacea from Hawaii and Samoa. Unil}. Calif. Pub. Zool. 26 (8): 159-164, ph. 12, 13. Philippi, A. 1839. Einige zoologische Notizen. Arch. Naturgesch. 5: 113-134, pIs. 3- 4. Sal's, G. O. 189'\. An account of the Crustacea of Norway with short descriptions and fif!,ures of all the species. Amphipoda, vol. 1. viii and 711 1'1'., 240 pIs., 8 supp!. pIs. Christiania and Copenhagen. Shiino, S 1948. Studies on marine crustaceans III. On a new boring amphipod, Chelura brc1'icauda sp. n. Misc. Rept. Res. Inst. Nat. Resources 12: 25-28, 3 figs. (in Japanese). 195'7. The marine wood-boring crustaceans of Japan. II. (Spaheromidae and Cheluridae.) Wasmann Juur. BioI. 15 (2): 161-197, figs. 1-15. Stebbing, T. R. R. [906. Amphipoda I. Gammaridea. Das 21, 806 pp., 127 figs. Sverdrup, H. U., M. W. Johnson and R. H. Fleming 1942. The Oceans . .. x and 10871'1'.,265 figs. Prentice-Hall, New York. White, A 1847. List of the specimens ()f Cmstacea in the collection of the British Museum, viii and 143 Pl'. E. Newman, London. LILJEBORGIID AMPHIPODS OF SOUTHERN CALIFORNIA COASTAL BOTTOMS WITH A REVISION OF THE FAMILY By J. LAURE1\S The benthic invertebrates of the coastal shelve" of southern California have been sampled quantitatively by a continuing program at the Allan Hancock Foundation. since 1952 (Hartman 1955. 1956 and Hartman and Barnard 1957). Much of the difficulty hampering the ecological analyses of these vast materials (amounting to more than 2,000 samples) has been the large number of undescribed species of polychaetes and crustaceans which com- prise the largest share of the fauna, more than 75% of the species of the bottom belonging to these two large groups. Prior to 1952 le"5 than 5% of the crustacean species were known. In order of numerical importance 1959 BARNARD: AMPHIPODS 13 the benthic crustaceans are amphipods, cumacean:;, tanaids, isopod:;, ostracods, pinnixid crabs, followed by other groups of minor importance. The cumaceans, tanaids and ostracods are virtually unknown. The pinnixid crabs probably have been largely described but need considerable revision. The isopods have been studied by Menzies and Barnard (in press, Hancock Foundation). Barnard has written a serirs of papers on the amphipods (Barnard 1954, 1955, 1955a, 1957, 1957a, 1958, 1958a) and has prepared a paper on the phoxocephalids (in press, Hancock Foun- dation). Dr. D. E. Hurley is preparing a paper on the Lysianassidae. In order of specimen abundance amphipod families are ranked as follows: Phoxocephalidae, Ampeliscidae, Lysianassidae, Oedicerotidae, Liljeborgiidae, Pardaliscidae and Haustoriidae, followed by scattered specimens in 35 other families; systematics of the first three families and the eighth is either published or in press. The fifth family, the Liljebor- giidae, is the subject of the present paper. The writer wishes to acknowledge Dr. Olga Hartman for her untiring concern to taxonomic problems of benthic invertebrates, and Dr. E. Yale Dawson and the Beaudette Foundation for providing support and publica. tion of this paper. Family LILJEBORGIIDAE Stebbing DIAGNOSIS.-Rostrum of head small; antenna 1 shorter than second; accessory flagellum present; mandible with poorly developed molar, first article of palp elongated; palp geniculate between articles 1 and 2; fourth coxa with upper posterior margin excavated; lower lip lacks inner lobes; gnathopods well developed; telson split to its base. NOTEs.-This diagnosis is considerably revised from Stebbing, 1906: 229. Several former diagnostic characters are no longer valid and have been omitted. The italicized portion provides the critical points for final determination. Liljeborgiid amphipods are quite plain and "normal" in the sense that they represent the typical textbook definition and figures of gener- alized amphipods. In this respect they resemble the family Gammaridae. hut differ from that family principally by the mandibular structure. REMARKs.-Nearly every modern amphipod systematist has com- mented on the identification difficulty in the Liljeborgiidae, and the writer has been no exception in the present reseaches. The difficulties in the five species described herein have centercd on the close similarity of all the species, especially the difficulty of separating the juveniles and females of the species. At first, it was believed that only two species were represented. However, one of the "species" exhibited three contrasting color "phases." These were studied in considerahle detail and qualitative (though subtle) morphological features were found to distinguish the species, especially in the males. The minute albino species was at first thought to be a recessive mutation correlated with early drath, Lut afkr conducting a 14 PACIFIC NATURALIST VOL. I, No. 3-4 sampling program in the middle of a bed of echiuroid worms a large number of minute sexually mature adults of this species were dis- covered in six of the twenty-two samples. Of particular confusion was the apparent hybridization or retardation of adults of one species which provided for a time a neat series of intergradations between two others. However, the large collections accumulated during the last years have demonstrated the relatively low rate of hybridization or retardation. Because of the close relationship of the several species it is difficult to decide whether some species are hybridizing or whether these aberrant intergrades are simply mutations. In all of these "hybridization cases" sexually mature animals have been found. However, female,; with eggs have been found only in a few specimens. The lack of eggs in the other hybrids may be due to the washing processes of the sampling methods causing their loss. The pre,;ence of eggs, of course, does not mean that they are fertile. In allocating the five southern California species to genera it hecame necessary to revise the family Liljcborgiidae as follows (see the original composition of the family in my Index to the Gammaridea, Barnard 1958) : LILJEBORGIA Bate (as in Barnard 1958) IDUNELLA Sars (revised to include) Idunella aequieornis (Sars) (type specie,;) Idunella ehilkensis (Chilton) Jdunella longirostris (Chevreux) (ex Sextonia) fJ5TRIELLA, new genus Listriella dahli (Schellenl,erg) (ex [dunella I Lislriella pieta (J\orman) (ex Idunella) Listriella melaniea n.sp. Listriella golPta n.sp. (type species) Listriella eriopisa n.sp. Lislriplla albina n.sp. Listriella diffusa n.sp. SEXTONIA Chevreux .. Idunella KEY TO THE GENERA OF LILJEBORGIIDAE 1. Gnathopod 1 larger than gnathopod 2 mUN ELLA ( = Sextonia) 1. Gnathopod 1 smaller or equal to gnathopod 2 2 2. Article 5 of gnathopods 1-2 strongly produced, slender and elongate; outer ramus of uropod simple LILJEBORGIA 2. Article 5 of gnathopods 1-2 weakly produced, thick and blunt, outer ramus of uropod 3 composed of 2 articles LISTRIELLA n.g. 1959 BAR:'IARD: AMPHIPODS 15 TABLE 1 Table of systematic criteria in Listriella from southern California UI .,j '0 bJ) 0 oj '"E '"'-' ;..oj '" '" £ '0 '"2", Q) '" .<: "';.. '" '0 bJ) '" ... t- "'E oj ", ... eD ft oj <: 0 0'" ....; -"'-'''' <lUI .<: .§ UI ... -e E c; '" oj '" " M,E ro d> rl ... oj ... " '" '" '0 II OUI .0 ar;;a .3::; ... " " UI ci ",,,, 0 '"E: '" 0 ,; g.'§' :k.- bJ) '"" PE 0)0. =:..r:: '0 <: '"» p:;'" Mol U is ..: '" ;:J ... >4'" >4 ;:J ..: Listriella MALE K 0 0 X X X X 0 X X X melanica FEMALE K 0 0 XXXX0 X X JUVENILE K 0 0 XXXX0 X X Listriella MALE D 0 0 XXXXOXX 0 0 diffusa FEMALE D 0 0 X X X X OXX 0 JUVENILE D 0 0 X X X X OXX 0 Listriella MALE DS H X X X X X 0 X X X goleta FEMALE DS H XOX XXX0 X X JUVENILE DS H 0 XXXX0 X X Listriella S X 0 X 0 0 () X XOO X eriopisa FEMALE S X 0 X 0 0 0 X XOO JUVENILE S X 0 X X XOOXXOXOO Listriella MALE 0 0 OXO X XOX OXX 0 X albina FEMALE 0 0 OXO X XOX OXX 0 JUVENILE 0 0 OXO X XUX UXX 0 K = dark S = striped DS = diffused-striped X = positive 0= negative OX and XO = intermediate H = mark 16 PAClFle NATURALIST VOL. I, No. 3-4 Genus ldunella Sal's ldunella Sal's; Stebbing, 1906: 234. Sextonia Chevreux, 1920:76-77 REMARKs.-Apparently Chevreux (1920) overlooked the fact that ldunella aequieornis, the type species of ldunella, has the first gnathopod consideraLly larger than the second gnathopod in both se>..es, for in Chevreux and Fage (1925) the two genera are separated \tith the erro- neous statement that the gnathofJods of ldunella are coequal in size. By restricting liljeborgiids with large first gnathopods to ldunella and removing the tYfJe species of Sextonia to ldunella it becomes necessary to create a new genus for the reception of the other two species assigned to ldunella (/. pieta and I. dahli) and the five species described all of which have the second gnathopod as large or larger than the first. Genus Listriella, new genus DTAGC"OSIS.-Liljeborgiid with gnathopod 2 as large or larger than gnathopod 1; fifth articles of gnathopods 1-2 weakly produced, thick and blunt: uropod ::I with outer ramus composed of two articles, always in juveniles, occasionally fusing to a single article in adults. TYPE SPECIES -- Listriella goleta n. sp. Listriella melanica, new species (Figs. 1, 2) DIAG'\'Osls.-Darkly pigmented in a characteristic pattern as shown in figure 1; specimens bleached in alcohol with article 2 of antenna 1 retaining a band of dark pigment which is characteristic and can be used as a critical feature in the southern California eyes well developed. Fig. 1. melanica n. sp. A female specimen 2.7) mm long from sta. 4847. 1959 BARNARD: AMPHIPODS 17 enclosed in a distinct capsule; gnathopods 1-2 with the palms of article 6 slightly more blunt and more transverse than in other southern California species (except L.