REPORT OF THE -@ CANADIAN ARCTIC EXPEDITION 1913-18 VOLUME VII: CRUSTACEA PART K: MARINE COPEPODA By ARTHUR WILLEY OTTAWA THOMAS MULVEY PRINTER TO THE KING’S MOST EXCELLENT MAJESTY r 1920 t Vol. vii—-60085 4 : Tsgued June 25, 1920 wn Report of the Canadian Arctic Expedition 1913-18. VOLUME VII: CRUSTACEA. : DECAPOD CRUSTACEANS. By Mary J. Rathbun...... (Issued August 18, 1919). Part B: SCHIZOPOD CRUSTACEANS. By Waldo L. Schmitt. (Issued September 22, 1919). Part C: CUMACEA. | By? We. Calman soe ysncy cor oe! taieinren mone vieaws Boas (Laepressy. Part D: ISOPODA. By MissP;, Boonie savers eaecd centauweamee beer ene ees (In press). Part E: AMPHIPODA. By Clarence R. Shoemaker............... 20.000 ee eet Un press). Part F: PYCNOGONIDA. Leon J. Cole................. eles Obeperac cies Sr es (In press). Part G: EUPHYLLOPODA. By F. Johansen..... ee ne ee eee (In preparation). Part H: CLADOCERA. By Chancey Juday...................00000- srinasiss toon (In press). Part I: OSTRACODA. Bye Ws batpeunsinswawrawshinenauaneendisednan boll n preparation). Part J: FRESHWATER COPEPODA. By C. Dwight Merch, an ees (Iesued April 21, 1920). Part K: MARINE COPEPODA. By A. Willey....... ee er *Uesued. 2.0002... 1920). Part L: PARASITIC COPEPODA. By Charles B. Wilson..................... (In press). : CIRRIPEDIA. By H. A. Pisbry. TA ida aoeeegh Hecele lske the Avot aaa oentostetes (In preparation). REPORT OF THE CANADIAN ARCTIC EXPEDITION 1913-18 VOLUME VII: CRUSTACEA PART K: MARINE COPEPODA By ARTHUR WILLEY OTTAWA THOMAS MULVEY PRINTER TO THE KING’S MOST EXCELLENT MAJESTY 1920 Vol. vii—69985—1 Issued June 25,, 1920 Cornell University The original of this book is in the Cornell University Library. There are no known copyright restrictions in the United States on the use of the text. http://www.archive.org/details/cu31924074095302 Report on the Marine Copepoda collected during the Cana- dian Arctic Expedition. By Artuur Wiutey, D.Sc., F.RS. McGill University, Montreal. The marine copepod crustacea, collected by Mr. Frits Johansen during the Canadian Arctic Expedition from 1913 to 1916, covers a wide extent of coast- line from Vancouver island to Coronation gulf in the Northwest Territories of Canada, the whole embracing an area which has been only slightly explored in regard to its micro-crustacean fauna. The comparison of this fauna with that of the Atlantic coast of North America offers remarkable similarities mingled with dissimilarities, as indeed does every other division of the North Pacific fauna. The facts discovered justify the expectation that further data will throw light upon the relation of the pelagic copepods to the currents prevailing off the west coast. These insignificant arthropods form the basis of the food- supply for pelagic fishes, especially for young fishes, whilst the littoral and bottom-dwelling species have nutritive value for the flat-fishes, either directly or indirectly. ; The copepod contents of Mr. Johansen’s samples were generally scanty, so that it was not always possible to indicate their percentage composition. In the present report several species are identified for the first time from the west and northwest coasts, but perhaps the most memorable marine copepod record for the entire expedition is that of Limnocalanus grimaldit from Collinson point, Alaska. It will be found that the collection secured by Mr. Johansen under such arduous circumstances presents several other features of interest. A notable deficiency is the absence, from all the gatherings, of Calanus cristatus which, according to Giesbrecht, is the most characteristic species of the Behring sea and has not been found south of that area. The explanation of its absence is to be looked for in the comparatively small number of stations made by the expedition on the voyage to the Arctic Ocean where their main objective lay. The number of copepods of the subdivision Harpacticoida taken pelagically by horizontal towing of the plankton nets at or near the surface, in water lanes amid pack-ice, or by vertical hauls through holes in the ice, makes a rather striking commentary on this collection. Just as the pelagic Calanoids make daily excursions to and from the deeper strata of water, so the benthonic or bottom-dwelling Harpacticoids evidently rise toward the surface from time to time. Only one pelagic Harpacticoid was recorded from the east coast waters during the Canadian Fisheries Expedition, 1914-15, namely, Halithalestris cront. This species has not yet been found on the west coast. The clear-cut specific divergence of Danielssenia stefanssont, in comparison with its Siberian congener, is another point worthy of special mention. A. CALANOIDA. 1. Calanus finmarchicus (Gunnerus, 1765). This prolific species is common to the North Pacific, North Atlantic, and Arctic oceans. According to the latitude, season, time, depth, and proximity to land or ice, in which it may be taken, it is found associated with very different companions. 1 Nore.—Most of the macroscopic forms in the Zooplankton (Fishes, Crustacea, Annelids, Meduse, etc.), were picked out before the samples were sent to Prof. Willey.—Frits Johansen. 69085—14 4k Canadian Arctic Expedition, 1913-18 Stations 18a, c,e,f,: 62° N., 167° 30’ W., four gatherings with net No. 3}, towing at surface for 5, 10, and 15 minutes, preserved in one vial, July 7, 1913. The quantity was small for the time employed in towing. It may be called an Acartva-plankton, since that genus was in the ascendant. There were also more than one hundred young Amphipods (Hyperidea), twenty-four crab larve (Zoex), and a few fish-larve. The following century of copepods, exclusive of the Acartia, was made out :— Taste I (Sta. 18, excy. AcarTra). Calamus finmarchicusig S27 SMM a cvcn dash ps aidoas Waeed Ba ok he HibeaaeN GaR RANA hon N ah 1 Pseudocalanus cloniqatusss:c ses ana Rah ey dg aus 399 g Wie nae aad aoa ken Gah Oe shan Ria RRA Sees 5 Cenironages momurricht > «oxy xe 2825 oba AY s EYRE RETRO Se Gtga lg eka ote ete BN as = pare ar 1 Hurytemora: herd mani: (Gt and'@) ss.gass chases teh pen take Rs tae eRAQ eae a Dae A GE MAE eer nERE 40 Paralabidocera amphitrites (all young)............0. 000 eee 52 LOVUUUDSOUSCOUDAUUS Ose. iis desciiststn shoab ni tan aGbe cd eked A Rion eG Rushes BAIR IL WEY LR OR 1 100 Station 21a, b, c: 68°30’ N., 166° 32’ W., temperature 45.6° F., August 15, 1913. Three gatherings of five minutes each at surface, with net No. 2?, yielded a fairly copious plankton of small Cladocera (Hvadne and Podon), Molluscan larve, Annelid larve, Meduse, 1 crab-larva (Megalopoda), young Amphipoda and some Copepods (table II). The station lies north of Bering strait, but south of the Arctic circle. The composition of the gathering indicates current action through the narrow strait. Tasuie II (Sta. 21a, b, c). Calanus finmarchicus, stages IV and V.. 1... eee eee 2 Pseudocalanus:elongatus: (chiefly 9.) 3. seasca a <.2e-nusa anes 4 ae a EES ek Be aR 25 Centropages MemurrtCHt soa os sigiyqde a agus dln tn gat eee atd A aod ptpsene ae on) a eS RETA erate Pa 2 Paralabidocera amphitrites (7 and @).. 22... eee e eee 15 Eurytemora herdmant (chichy G) «2 .Qx oe 25 Burytemora-johansent, (Go! and: ) 5 2 v0-nesyeg seus 494 PERN Reha SRE ED Eee Pa EET Sageeee ase 9 ACOTUG LON GU CNIS 3-00 5 3.68 cogs a ebkos Sok pk GHA ed REG a BAB Lp WAESEA MH LEAS LEAS SE SE PE SSS 10 PCG US 5 sks FG Seen Bcc 2 Svea Sigh WS Apole et BIAS alc WIRE A GOSS AOS ERE ES GEG BS 10 OURO ISUNTUAS., 5 paca sc sectsces ceo hovtainly i chen Bia al vaceg ces dg So dou dens hpnboenoBiHe DLR, Ps Baoasey eens 2 100 Station 25b, c: off Cooper island (point Barrow), Alaska, within the Arctic circle; depth two fathoms; August 27 and 28, 1913. Two gatherings of ten minutes each with net No. 3, at surface among ice, contained some very young Calanus. Tase III (Sta. 258, c). Calonus finmarchicus J. son44u's gees es Ramee ds 32 Ue eee es. FEELS OS: See BRE 3 Calan us: RINGRENL CUS LD 5 scsi at) ies cnceshad Ge GAbea ie Ale hud nist Ba edad haat PAGS aE dows lew, | vbaageeG 3 Calais fininianchveiis INT oii ceciccntcaieca souk ugly ataobvedenes ¢ Jo eo (Abe MN SO RoR os 2 COlanus PHMATCRICUS TY ca soci ccsmotuas SshG Kean Ganenans wo ese & Loci 2 PSQuMdocalands: CLONGOLUS «2d cnuge ae cure h Gee Shas A FEMSACGARRRE TERRERRTA aon aoe 2d ACatHG (CLGUSUBNANONGUOMES) c-sc-c0 naar see Te RP ARERR EEG GMS HED KREME ROgAD EE 60 CDT OTL SUIT LES asi onset cache eel ce ha a lk deca ahem Dea gags be TR Don GSMA inde AINA Re 3 Harpacticus! GMMaAtune ian guna dna cnae Wa ceetayqidinig- ate tpn geese awe year gs eee ene eRe 2 Dajielssenia: fustpormisss csgou s sohn Av des ae bas eR AL ERR EL SESWA DOSS SUES AGRE REED ES 1 100 Station 27r: Collinson point (Camden bay), Arctic Alaska; depth 1 to 2 fathoms; October 2, 1913. A short haul with catcher? from one fathom to the surface, under ice ten inches thick, captured a male of Metridia longa in company with C. finmarchicus V, and young Pseudocalanus. _ .} This plankton net was made of coarser silk, closed at the end, nine inches wide at the mouth, twenty inches long. 2 Full-speed net of fine silk, two inches across mouth, two feet long, with bottle at end. 3 See footnote p. 6 K. Marine Copepoda 5K Station 27t, u: same locality and depth as preceding, October 4 and 5, 1913. The following assemblage (table IV) was taken through a crack in the ice, one to two feet below the surface, with net No. 3:— \ Tasie IV (Sta. 270, u). Calanus finmarchicus IV, V and 9 10 Calanus hyperboreus IV and V 4 Pseudocalanus elongatus......... 54 Limnocalanus grimaldti (# and 9) 10 DUE ON Gs SULA te Se 8 esa aca age nee 4 Aino veLalagata mr ahalerl a wile #ave 20 OME CER CON AS ENO toga toa Pies eee ER a on esed oy) Abeee Stet ted Se oe ssh sae tects Batak oie bap eek oe 9 aa ree ee 2 100 In addition there was an Ectinosoma, a Pseudobradya and an Acartia. The presence at this station of Limnocalanus is of particular interest, as will be detailed more fully below. One C. finmarchicus ¢ measured 4.25 mm., another 4.5 mm. : Station 27y2: Entrance of lagoon at Collinson point; depth 1 to 2 feet inward current, no ice, net No. 3, fifteen minutes, October 8, 1918. TaBLe V (Sta. 27y2). Calanus-fiimarchicus UV ccc oils 2 hides boas SASS WAR RS, bE ESA A ee the ad eat Ways © 1 Calanus finmarchicus Vi... 66. cece ccc eee e ee bb eee eee te bbbenee 7 CLOTS PUT CH TOUS Osc ag neste esr ee aa fete ACPA G6 out id BUG bod abd tte tess E eb ae AaB 1 Calamiis My perUOreUis: V asrscacs cee son aad aes ales AL S's ee ERA g BE Sa WOVE ae Be eeS 1 Pseudocatanis elongates WL. cn su\eqiew dan 3a oa bac oaeaa Oar ies GELIEG Be CATS OE REIMER F 10 Psetidocalanus elongatus VW g3.13 vhs pins wets Ss gos Bok RE BRE HO HRS Bis DEK GH DERG WS Cees BROS 20 Pseudocalanus elongatus V. 30 _Pseudocalanus elongatus 10 Gaidius (immature)...... 10 Oithona similis.......... 10 100 Station 29e: 70° 3’ N., 141° W., depth 25 fathoms, April 2, 1914. Three vertical hauls with net No. 3, from 0-20 fathoms, through crack in ice, yielded one C. finmarchicus ¢ and two or three immature male Pseudocalanus. Station 29g: 70° 20’ N., 140° 30’ W., depth 150 fathoms, April 6, 1914. Several vertical hauls were made, at various depths with plankton net number 5! through cracks in the ice. The captures comprised C. finmarchicus, young and adult, including a female of 5-5 mm., and a male of 4-5 mm., in company with Calanus hyperboreus, Pseudocalanus elongatus, Euchaeta norvegica (see below), Metridia longa and Otthona similis. Station 41s: Bernard harbour (inner harbour), Dolphin and Union strait; temperature 35-3° F., net No. 3, ten minutes at surface, August 24, 1915. Tasie VI (Sta. 41s). Calanis finmarchactis TaV .xsissay eines See nics oe aR an Le Seek f ad eatenas Sata gine Bi afe au 22 Calanus hy perboreus Vis ssvvered ctu deceet thes obec oy ane da cs Ae ciss Uy taavanots Ge tesa amas 1 Pseudocalanus elongatus: o.i¢ EK eee eae eekae 1 Galanws HimanchiouS Vegan kph te Hea SoS a OS Oars aaa oe aun Yura SANA RAMESH ee 2 GCalanius Aimarcnicus Qs iin 'c cece wanleneed SAREE bea ogame ga Hae He lettin BN Bioeng HSE ESR SEE Se 2 2. Calanus hyperboreus Kroyer, 1838. Besides the occurrences of this species noted in Tables IV, V and VI, there are several other records to be mentioned. Station 27y1: Lagoon at Collinson point Alaska, in 1-2 feet of water, no ice, October 8, 1913, catcher. One C. hyperboreus V, length 5-6 mm. The lateral lobes of the last thoracic segment were triangular and bluntly pointed, so that doubt might be entertained about its identification until the fifth legs, with 17 coxal teeth, were examined. The inner and outer branches of the fifth legs were 2-jointed; the remaining natatory legs had both rami 3-jointed. The anterior antenne were 25-jointed, joints 8 and 9 being feebly separated. Station 28b: Collinson point, Alaska, depth one fathom, ice 12 inches thick, ‘October 14, 1913, catcher. One C. hyperboreus IV, length 4-7 mm. was taken The abdomen was three-jointed; p 45 Re and Ri, one-jointed; the remaining legs had two-jointed rami. The jointing of the antenne and mouth-parts was the same as in the adult, joints 8 and 9 of the anterior antenne being imperfectly divided. Station 28e: Same locality, ice 16 inches thick, October 21, 1913. One female of 8 mm. was taken in the catcher. Station 2993: 70° 20’ N., 140° 30’ W., depth 150 fathoms; vertical haul with net number 5 from 50 to 150 fathoms, April 6, 1914. Two mature females measuring 7-5 and 8-5 mm. in length. Station 30a: 69° 41’ N., 141° 11’ W., off Demarcation point, Alaska, about 300 yards offshore, depth 3 fathoms, May 4, 1914. Six vertical hauls with net number 3, from surface to bottom, through a hole in the ice which was six feet thick. The total number of copepods preserved was 74, distributed as under. 1 The bag of the catcher was made of bobinette, having wider meshes than any of the plankton nets Marine Copepoda 7K Taste VIII (Sta. 30a). Calaniua hy perboreus LV vss ciinesnes Coes Ga wees 3a Gane eed ou Sod oad Bib p dind He Foe RY Cn BRS 1 Pseudocalanus elongatus Ilo: eccac stay cree tenbet BS hoe TUE be gk bE Phe Ricks bathed Has ae 1 Pseudocalanus elongatus IV ..... 0.0.6 ccc cece kent e sence ee teeenentntntennnes it Pseudocalanus elongatus Vi... 0.0.20 ccc cee ete e tee eeveveretenns 42 Pseudocalanus elongatus 2.0.0... 0 cc cece ete beeen tc eveeeeenes 11 Pseudocalanus clongatus Po iecec ccc cence eben eben bebe beset beer tneeturbees 5 OURO SU MTAS ses Scute S oe Bx eee icra genh io fe He onan aT o8E cok MGS GaebEG ABS ed eld ate eae 5 OM CRO CONTT ER Gry Srecte mise a cceceoeimtatea aie Tatok a WE A Se aa orn eaes Neeson els aN SARS AEROR welt e 1 Harpacticus superflezus.......... ote YE ee LTO BAG GER DER BED ORS ERE PEERS Put ES TREE 1 74 Station 41p: Bernard harbour, Dolphin and Union Strait, Northwest Territories, beach water, in the catcher, August 14, 1915. One female 8-25 mm. long without the fan of caudal sete, 10 mm. long including the caudal setae. A coloured drawing by Mr. Johansen shows the body nearly uniformly red, the anterior antennae deep red. Station 41u: Bernard harbour, end of August, 1915. Four mature females were taken from the stomach of a Western Charr or Dolly Varden trout, Salve- linus malma, W. I wrote about this interesting find to Mr. Johansen who kindly informed me that practically all the specimens of the Dolly Varden trout which he obtained in the north were caught in salt water. A large lake east of Bernard harbour, contained individuals which had not succeeded in getting back to the sea before the creek froze up, so that they had to stay in the lake for the winter. 3. Calanus tonsus Brady. G. 8. Brady: Report on the Copepoda. Challenger Rep., vol. VIII, p. 34, 1883. This is a normal-looking Calanus, like C. finmarchicus, but characterized by the absence of basal serratures on the fifth pair of legs. It was taken by the Challenger Expedition chiefly in the southern hemisphere but also, in com- pany with Calanus propinquus Brady, in the surface tow-net at station 241, between Yokohama and Sandwich islands, over a depth of 2,300 fathoms in lat. 35° 41’ N., long. 157° 42’ E. Three damaged specimens of C. tonsus, stage V, were contained in the gathering from C. A. E. station 13a, 6, c, three surface tows of five minutes each, lat. 54° 30’ N., long. 159° 42’ W., July 1, 1913. The gathering was scanty but included Acartia tumida n. sp., Acartia longiremis, and Harpacticus untremis. C. tonsus was the species referred to without name in my report on an investigation into the Pacific Halibut Fisheries.!. I saw numbers of them in an inlet to the south of Tassoo harbour, on the west coast of Moresby island, south of the San Christoval mountains, Queen Charlotte islands. In the evening of May 22, 1914, ‘they were rising to the surface amongst the kelp, one by one, then swimming round in spirals, clockwise, causing distinct widening ripples at the surface.’”’ These were also immature. From the peculiar distribution of this species it may be anticipated that future investigations will disclose a special connection with oceanic currents. 1Published in the Canadian Bluebook: Contributions to Canadian Biology (1914), Ottawa, 1916. 8K Canadian Arctic Expedition, 1913-18 4+. Pseudocalanus elongatus (Boeck, 1864). This species shares with Acartia the quality of being the most abundantly represented in Mr. Johansen’s gatherings. In addition to the stations tabulated above, the following have to be added. Station 13g, h: 54° 30’ N., 159° 42’ W., two surface tows of 15 and 30 minutes, net number 3, July 1, 1913. The gathering was very scanty, a female Pseudocalanus being present, together with traces of Metridia, Acartia, Har- pacticus, and Cypris-larve of Cirripedes. Station 20a: Grantley harbour, Alaska; depth two fathoms, surface tow 5 minutes, net number 3, July 30, 1913. This was a Cladoceran plankton, numerous Hvadne and Podon, with strong copepod infiltration, and some Mollus- can and Annelid larve. Acartia clausi was almost as abundant as were the Cladocera. Taste IX (Sra. 20a). Pseudocalanus elongatus, scarce; 7,2 and young. Centropages memurrichi, abundant; 9 and somec. Eurytemora herdmani, two ovigerous females. Eurytemora johanseni, males only noted. Acartia clausi, very abundant. Tortanus discaudatus, one female. Idyea furcata, one female. Station 40d: Bernard harbour, water depth 9 fathoms, six vertical hauls 0-5 fathoms with net number 3 through hole in ice, June 8, 1915. Female and immature male, the latter with four-jointed urosome but anterior antenne 19-jointed as in adult male. Station 429: Bernard harbour (outer harbour), surface tow with net number 3 for 10 minutes, September 30, 1915. The scanty gathering included a few Pseudocalanus, mostly young. There were also present: Hurytemora herdmani 2, Otthona similis, Harpacticus uniremis, Idyea furcata, Danielssenia stefanssont. Station 42y: Dolphin and Union strait, off Bernard harbour, depth 17 feet, ice 24 feet thick, December 6, 1915, timenoon. Six vertical hauls from sur- face to bottom were taken with net number 3 at low tide with an eastward current. There were upwards of 100 small copepods. The Pseudocalanus were of various ages, abdomen two to fourjointed, all immature. TaBLpe N (Sta. 42y). PSEWAOCOIINUS 1ELONG AT UE cies. shige ienteagiitn Se lea Beek eae cam Ss Ree BR eopeomel is oselannEeeS 40 IVE CUPCAUG LONG Oxia) secivtula beni ein dis te wigan ROE ta 3 2 eke eR aR eke oss Bee Bae A BRON SA 8 A COTO LON OTNONIUS we cipendi he wma aningan ae nqueds a Mise she vcce G schalsa Gugtose dosed madeeny Baia heat e Rubies ee 2 OGTR SUT S es 5 Gea Bh hy ws Se BGs ot nase hsttrkoe® kesh pcasedigesg Gad ae day of Bighodcka tein br og dakota dig Seer 38 ONCRONCON CLG Sirk cas cans ctesitasy seded yack en vsvau hep anbegectd il gabe co bot ead 8 eat GA baie da gach gh esa anced 2 UL COM UR CCE Claes 8 anti seedy yeh kee eh tls actrees nse Reg nh a stores cnc chet actnds 8dste RIels 10 100 Station 422: Same locality and depth as preceding; time midnight; three vertical hauls with net number 3 from bottom to surface through hole in ice; water temperature 29-2° F., December 12, 1915. Both males and females were taken, incompany with Idyea furcata, Metridia longa, Acartia longiremis, Oncaea conifera and Thawmaleus bernardensis. A female Pseudocalanus from station 27t, u, (above table IV) had a two- chambered cyst attached to the right anterior antenna, with faint indication of radial arrangement of the brown granular contents (Fig. 1). Similar parasites, questionably assigned to the Infusoria, were observed and figured upon Calanus Marine Copepoda 9x finmarchicus by T. Scott [15th Ann. Rep. Fishery Board, Scotland 1896 (1897) p. 172, pl. III, f. 22.]_ They are now believed to belong to the Peridinea and have been named Ellobiopsis chattoni by Professor Maurice Caullery.! Fig. 1. Portion of right antenna of Pseudocalanus from Collinson point with Ellobiopsis chattont Caullery attached to it. According to Carl With (Copepoda I. Danish Ingolf Exped., vol. ITI, part 4, p. 57, Copenhagen 1915) this long established species should be known in future as Pseudocalanus minutus (Kroyer 1845-47). 5. Gaidius sp. juv. Only immature examples of this form occurred in the gathering from station 27y2 (above, table V). They were mostly immature males. Front obtuse, rostrum obsolescent or absent; length of immature 7, 1-92 mm.; fifth feet of immature male biramous (Fig. 2). Fig. 2. Gaidius immature, abdomen 4-jointed. R. Right fifth leg. L. Left fifth leg. I had at first entered them in my list as Chiridius obtusifrons because of the absence of a rostrum and the presence of short lateral acuminations of the last thoracic segment. The male of Aetideus armatus is likewise devoid of a rostrum, but according to Sars this species has never been found anywhere in 1M. Caullery (Paris): Sur un parasite de Calanus helgolandicus Claus, appartenant probablement aux Peridiniens (Ellobiopsis chattoni n.g.,n.sp.). Verh. VIII, Internat. Zool. Kongresses zu Graz 1910, Jena 1911, pp. 440-442. The complete description appeared in Bulletin scient. France, Belgique, t. 44, 1910, fase. 3, 201-214, pl. V. 10k Canadian Arctic Expedition, 1918-18 the Arctic ocean, and the adult male is only 1-45 mm. long. Aside from the presence or absence of a rostrum, the Canadian Arctic forms agree with Gaidius tenuispinus in having the inner branch (Ri) of the second legs (p.2) two-jointed and in lacking an outer seta (se) on the first joint of the outer branch (Re 1) of the first legs (p. 1). Sars observed that G. tenuispinus sometimes occurs in the same gatherings with Ch. obtusifrons, both species ranging through the Polar basin crossed by Nansen. ; The inner ramus of the mandibular palp is not so “unusually small’ as is required by the definition of Chiridius; the teeth of the mandible have simple points. The anterior antennae are 24-jointed, joints 8 and 9 being coalescent, the terminal joint distinct and short; the entire appendage is not longer than the forebody. The second basal joint (B2) of the second maxilliped (mp2) is hardly longer than the B1; the first inner seta (si) of B2 is inserted distad of the middle of the joint, the portions of the joint proximal and distal to the insertion of this seta being as 2: 1. 6. Euchaeta norvegica Boeck, 1872. I noted only a single damaged immature female, with three-jointed abdomen, in the gathering from station 2994, depth 150 fathoms; a vertical haul with net number 5 from 0 to 50 fathoms in an open water lane in pack-ice, 70° 20’ N., 140° 30’ W. There was a very small quantity of plankton for such a great column of water. In the same vial with the Euchaeta there was one .Vetridia longa ¢, and half a dozen Orthona similis. Euchaeta norvegica is a characteristic North Atlantic and Arctic species. It occurred at numerous stations in Dr. Hjort’s Canadian Fisheries Expedition 1914-15,! but not in Professor Herdman’s traverses of the Atlantic to which reference will be made later. At Passamaquoddy Bay it forms part of the food of the Pollack. 7. Centropages mcmurrichi, n. sp. This species occurred at several stations already mentioned: Tables I, II and IX. It was first obtained off the British Columbian coast by Professor J. Playfair MceMurrich? in a patch of ‘“‘brown water” off the entrance to Esperanza inlet , on the west coast of Vancouver island on September‘11, 1912. He identi- fied it as Centropages hamatus (Lilljeborg 1853), whilst noting differences in the armature of the genital segment of the female and in the structure of the fifth legs. It has the ventral recurved hook of C. hamatus ¢ in front of the genital pore but the remaining setulose armature of the genital segment is distinctive. The other principal specific character is afforded by the strong unguiform process on the inner side of the second joint of the outer ramus of the fifth foot (p5 Re2 ¢). In C. hamatus this process is smooth and less than half the length of the third joint (p5 Re3). In the present species the process is at least two-thirds the length of Re3 and is denticulated along its outer edge. The relative dimensions of anal segment and caudal furea in the female are: anal segment 6, furcal length 11, width of fureal ramus 3. In addition to the stations named above, a single female, accompanied by numbers of Paralabidocera, was taken at station 21 d,e,f, with net number 8, 68° 41’ N., 165° 10’ W., temperature 45-5° F., surface, August 16, 1913. Afemale from station 20a, July 30, 1916 (Table IX) carried a spermatophore. The spinules on the genital segment of the female include a pair of antero- ventral groups arranged in a comb-like row right and left of the swollen base 1A. Willey: Report on the Copepoda obtained in the Gulf of St. Lawrence and adjacent waters 1915. Canad. Fish. Exped. 1914-1915. Department of the Naval Service Bluebook, pp. 173-220, Ottawa 1919. 2 J.P. MeMurrich: Notes on the Plankton of the British Columbia Coast. Trans. Roy. Soc. Canada (ser. III), vol. X, September, 1916, p. 77-8, f. 1-8. Marine Copepoda 11K of the hook; a right lateral comb-like group of strong spinules near the middle of the segment and a left postero-lateral group of much smaller spinules near the posterior end of the segment; also right and left dorso-lateral tufts in the anterior region. The segment itself and the groups of spinules are asymmetrical. 8. Limnocalanus grimaldii (J. de Guerne, 1886). This noteworthy species occurred in one gathering only, at station 27 t, u, Collinson point, Alaska, October 4 and 5, 1913, forming 10 per cent of the copepod content (table IV). The lateral edges of the last thoracic segment (Th5) have an acute point set in the middle of the border and do not taper to the point; total length of female 2-85 mm. The caudal furca is long, two-fifths the total length of the urosome; the upper and lower surfaces of the caudal rami are beset with short spines, the inner and outer surfaces are setulose (or “ciliated”). Abdomen of female three-jointed; of male five-jointed, with spines on dorsal and ventral borders of Ab 2, 3, and 4. Right geniculate antenna of with five joints beyond the bend, the first of which is long, the last very small. It has perhaps the most remarkable distribution of any marine copepod. Jt was first taken in the Gulf of Finland and named in honour of Prince Albert of Monaco by J. de Guerne in 1886. Two years later it was declared by Nord- quist' to be identical with Limnocalanus macrurus G. O. Sars 1862 from the Scandinavian lakes. Its validity as a species distinct from the freshwater form was proved by G. O. Sars who found it in material from the Caspian Sea, where it constitutes part of the relict glacial fauna of that basin.? The same species (L. grimaldii) was recorded by Sars living pelagically in the estuary of the river Jana in Siberia. The length of female examples from Siberia was 3.30 mm., as against 2-80 mm. from the Caspian Sea. The largest individual observed by Nordquist in the Baltic was 3-15 mm. long. Sars regards it as a true Arctic form of marine origin and “its occurrence in the Baltic and in the Caspian sea must be explained by a direct connection in former times of these basins with the Glacial sea.’’ There is a slight difference apparent between the figures of the falciform process at the end of the outer ramus of the right fifth foot of the male, given by Sars for L. grimaldit (1897 op. cit.) and for L. macrurus in his Crustacea of Norway, vol. IV Copepoda-Calanoida, Part VII and VIII, pl. 55, Bergen 1902. According to these figures the process is broader and shorter in grimaldii than in macrurus. The examples of grimaldit from Alaska agree in this respect with macrurus. There is a prominent ental cone on the first basal joint of the left p 52, corresponding with fair approximation to that indicated in the figure by Sars, 1897, op. cit., pl. 4, f. 18. 9. Eurytemora gracilis (Sars). Temorella gracilis Sars (Jana Expedition, op. cit., 1898, p. 336). This species was originally taken in the lower part of the river Jana, in the same locality as Limnocalanus grimaldti. A single damaged female, referred tentatively to EF. gracilis, occurred in the gathering from station 21 d, e, f, lat. 68° 41’ N., 165° 10’ W., temperature 45-5° F., August 16, 1913, surface. The 1 Oscar Nordquist: Die Calaniden Finlands. Bidrag till Kainnedom af Finlands Natur och Folk, vol. 47, pp. 191-275, 10 pls. Helsingfors 1888. 2G. O. Sars. Pelagic Entomostraca of the Caspian Sea. Annuaire du Musée Zool. de l’'Acad. Imp. des Sciences de St. Petersbourg 1897, pp. 38 to 49 of the reprint which I owe to the courtesy of the author. 3G. O. Sars: The Cladocera, Copepoda and Ostracoda of the Jana Expedition. Annuaire Mus. Zool. St. Petersbourg, IIT, 1898, p. 335. 12k Canadian Arctic Expedition, 1913-18 terminal sete of the natatory legs in the original description are cultriform, dilated in the middle. Owing to the state of preservation of the specimen at my disposal, I can say nothing on this point. ; The length was 1-52 mm., the anterior antenne were broken. Relative lengths of anal segment and caudal furca: anal segment 9, furcal length 15, Fig. 3. Eurytemora gracilis?. Urosome from above. Fig. 4. Same. Part of fifth leg. width of caudal ramus 2; surface of caudal rami smooth (Fig. 3). In the last pair of legs (p. 5), the distal joint was lost; the unguiform process of the proximal joint of the Ramus (Re 1) projects nearly horizontally inwards, abruptly narrowing to a distal acuminate portion which is ciliated on the inner edge (Fig. 4). Genital segment with lateral convexities separated by a constriction (Fig. 3). 10. Eurytemora herdmani I. C. Thompson and A. Scott, 1898. This is one of the most typical and abundant Copepods of the gulf of St. Lawrence. It was first obtained in 1897 by Prof. W. A. Herdman, who collected surface plankton through the ship’s pump continuously day and night whilst the steamer was going at full speed across the Atlantic. Though not previously observed on the Pacific coast, it was taken at a number of stations by the Can- adian Arctic Expedition: Tables I, IJ, VI, VI, IX, station 42p (under Pseudocalanus), and the following. Station 17 a, b, c: 60° 9’ N., 167° 38’ W., three surface hauls, with net number 3, fifteen minutes each, preserved in one vial, July 6, 1913. Numerous small copepods, mostly adult 7, some young forms, but not one female. TasLe XI (Sra. 17a, b, c.) Eupytemora Nerd mane acaniancn ean Gwe 4 wee 28 KURA Se RRRNS SSE R EMU EY CORE SESE SF RU DEE 45 ACOHUG. Sea 2 nes, oxic cuit SIE Red Se LO Loe LEN SRAM. ORR ONDE EE ae Rack ey BB Mousa ued wines Ba aeeD 45 TOP UGIVUS: US COUGCNUS Iie ss ay sicccgce, 55.4 thay Bk Gian eA hE So BMS OONS [oa whKOS Bs chased cy do siagobasud. ususnld euauadienie leah Wie 10 100 Probably both Acartia longiremis and A. clausi are present in subequal numbers, but as the metathoracic thorns of longiremis may be lost or worn down, it is not safe to differentiate these species by male characters. Another vial of the same date, labelled Sta. 17e, surface 30 minutes, same locality and net, contained a scanty gathering which included some Euphausiid eggs, one male Eurytemora herdmant, and a number of Acartia longiremis, both male and female. To begin to understand these relations it would be necessary to know approxi- mately the time of day and the light conditions. In any case the assembling of males, as displayed in the table above, is not too commonly observed. Station 19: See under Acartia longiremis. Marine Copepoda 13k Station 36: Off cape Lyon, Darnley bay, Northwest Territories, five minutes tow in surface, with net number 4,! from ship, water depth five fathoms , August 23, 1914. Only eight copepods preserved, all males: five Acartia longiremis and three Hurytemora herdmani. One of the latter was 1-20 mm. long; a male from station 21 (Table II) measured 1-36 mm. Station 41g: Bernard harbour (outer harbour), surface net number 3, five minutes, August 1, 1915. One female in company with Cyclopina schneideri, Harpacticus uniremis and Harpacticus superflexus. 11. Eurytemora johanseni, n. sp. This species was taken in company with HE. herdmani (Table II and Table XII),from which it may be recognized externally by the length of the caudal furca. Whereas EL. herdmani is longifurcate, the furca much exceeding the length of the anal segment, H. johanseni is brevifurcate, the furca and anal segment being subequal in length (Fig. 5). Fig. 5. Eurytemora johansent 9. Dorsal view of hind-body. Description of female: total length 1-28 mm., anterior antenne as long as forebody; length of caudal furca 0-112 mm., of anal segment 0-104 mm., wings of genital segment small; mouth-parts as in EL. velox. The fifth legs (p. 5¢) are four-jointed as in the type species; the unguiform process of the penultimate joint (Re 1), not exceeding Re 2 in length, is coarsely denticulated on its outer side; the right Re 2 (distal joint of the appendage) is larger than the left and crenulated on its inner border (Fig. 6). Fig. 6. Same. Fifth legs. Description of the male: total length 1-12 mm. The anterior antenne are to be distinguished from those of E. herdmani on close inspection (Figs. 7-10). In both species, the intumescence in the middle section of the right antenna is formed by joints 13-18 inclusive. Of the two distal joints beyond the bend, the penultimate joint is to the terminal joint as 5: 8 in herdmani and as 4: 5 in johansent. In other words, the penultimate joint of the right antenna of £. 1 Net as net No. 3 (see note p. 4K), but made of fine silk. 14k Canadian Arctic Expedition, 1913-18 johanseni is subequal to that of E. herdmant, but the terminal joint is shorter than in herdmani. Again, in E. herdmani, joint 12 carries a long curved ungui- form spine commonly applied to the face of the antenna, though capable of being extended forwards. In E. johanseni, joint 12 carries a spine standing out at right angles to the face of the antenna, less than half the length of that of | a = Figs. 7-10. Details of right antenna of male. 7. E. johanseni, distal joints. 8. E. herdmani, same. 9. EH. johansent, spine on joint 12. 10. E. herdmani, same. herdmant, slightly curved and minutely bifid or flaring at the tip. Other spines occur on the proximal joints but only the spine on joint 12ghas specific value. In both species the right antenna presents a proximal as well as a‘distal swelling with short narrow joints intervening. Fig. 11. £.johanseni 6. Left p. 5 B2 Fig. 12. Same. Fifth legs from behind. Fifth legs (p 5 «#): the left B2 shows a strong ental protuberance (Fig. 11); the inner margin of the right B2 is entire; the terminal joint of the left foot with subdistal spoonshaped expansion (Fig. 12). In EH. herdmani there is a prominent cylindrical ental tubercle at the proximal end of the right B2. Marine Copepoda 15k In one specimen the caudal furca was asymmetrical, suggesting a mingling of characters, as shown in Fig. 13. The arrangement of the sete on the natatory legs agrees with that of E. velox, except that the third joint of the outer branch of the first foot (p. 1 Re 3) Fig. 13. #. johanseni 6. Abnormal caudal furca. is furnished, as in E. herdmani, with seven sete (2 se, 1 st, 4 si); in E. velox this joint has six sete (1 se, 1 st, 4 si). 12. Metridia longa (Lubbock, 1854). Station 27r. Collinson Point, Alaska, October 2, 1913: one male, with the left anterior antenna geniculate; length 3-88 mm. Station 29g. 70° 20’ N., 140° 30’ W., depth 150 fathoms: several vertical hauls with net number 5, from 0 to 150 fathoms, April 6, 1914. The gathering, amongst others (see under Calanus finmarchicus), contained females and young; one female was 4-88 mm. in length. Station 42y. See Table X. Young individuals. Station 42z. See under Pseudocalanus. A young Metridia longa of 1-67 mm. was taken. From these scanty records it is evident that this representative Arctic species was only present in traces. Its abundance at suitable places in the north is shown in the following extract, which I have not seen quoted before, from A. E. Nordenskiold: The Voyage of the Vega round Asia and Europe, translated by A. Leslie, London (Macmillan) 1881, vol. II, pp. 54-56: “ The common idea that all animal life ceases when the interior animal heat sinks under the freezing point of water, is not quite correct. This is proved by the remarkable observation made . . . during the wintering at Mussel Bay in 1872-73, that small crustacea can live by millions in water-drenched snow at a temperature of from —2° to —10°-2 C. If during winter one walks along the beach on the snow which at ebb is dry, but at flood tide is more or less drenched through by sea-water, there rises at every step one takes, an exceedingly intense, beautiful, bluish-white flash of light, which in the spectroscope gives a one- coloured labrador-blue spectrum. It produces indeed a peculiar impression on a dark and stormy winter day (the temperature of the air was sometimes in the neighbourhood of the freezing-point of mercury) to walk along in this mixture of snow and flame. On a closer examination, it appeared that this light-phenomenon proceeded from a minute crustacean, which, according to the determination of Prof. W. Lilljeborg, belongs to the species Metridia armata A. Boeck (= M. longa). When the temperature [of the snow-sludge] sinks below —-10° C., the power of this small animal to emit light appears to cease.” 16K Canadian Arctic Expedition, 1913-18 13. Metridia lucens Boeck, 1864. I have only one record of this species in the collection: one male, 2 mm. long, at station 13g, h, 54° 30’ N., 159° 42’ W., July 1, 1918, at the surface. It has been reported very common, summer and winter, in the San Diego region. 14. Paralabidocera amphitrites McMurrich, 1916. Station 14. 54° 23’ N., 164° 45’ W., surface, 15 minutes, net number 3. July 2, 1913. Two males in company with an ovigerous Harpacticus uniremis. Station 18. Table I; many young, but no adults, were taken here, and again at station 19 (see under Acartia longiremis). Station 21a, b, c. Table II, young and adults of both sexes. Station 21d, e, f. 68° 48’ N., 165° 10’ W., net number 38, three surface hauls of 15 minutes each, temperature 45-5° F., August 16, 1913. Taste XII (Sra. 21d, e, f). Ceninopages: Memurineht Orcager ics Lmdcen god wei &-Whae doe Reams ed wees hlak eed as sees 1 Buryteniond: QROCIUIS Qiao jack lela tla Mave Gatien chica. © evi eaabiala ear amaredne oimeaid| AoaeMendecshs 1 Eurytemora herdmanid...-...0..00025.. eae. BIA, Barationg paganwe ce inulin Lagging 4 Hurytemora Nerd Man. 9 sissckevese oh A ete Bas Weveeca ae sas Ohige ate seranais Benes 3 Eurytemorajonansent Os. xeegpsade ayan Aeaode 4 SHRTEEOE REE WE PEI S EERE S Pha eee . 36 Eurytemora johansent 9.2.2.0... 0.000 6 Eurytemora johansent 2 stage V...... 4 Paralabidocera amphitrites @ . a Pte & 4 Paralabidocera amphitrites 9 stage Neoace 14 Paralabidocera amphitrites 2 stage IV. 3 Paralabidocera amphitrites 7... . ee 5 Paralabidocera amphitrites & stage We mach sen 6 Paralabidocera amphitrites stage IIT... 00. cece ee 4 Acartia (clausi=lon gives): CO waaniis aq-0'5 we G'4 4 GOs e 5:2 GOR EET A WPALS RS OKE BY OGS et EES OSEE 9 100 Professor MecMurrich’s material consisted of two females and one male, collected by himself in September, 1912, from a patch of ‘brown water,” about 3% miles off Amphitrite point, Vancouver island.2 They were sub-mature specimens, not having achieved the final ecdysis, and whilst they exhibited certain generic features, the specific characters were in part lacking. The missing characters relate chiefly to the right anterior antenna of the male, the fifth pair of legs of the male, and to the genital segment of both sexes. In the male, the fifth feet undergo a remarkable transformation on the passage to maturity. The lateral cephalic hooks and the rostral processes are like those of Pontella and some species of Labidocera. Paralabidocera further agrees with the definition of Labzdocera in the absence of a rostral lens, in having the dorsal eyes contiguous in the male, and in having less than seven teeth on the mandible. It differs from Labidocera and agrees with Pontella in having 24 joints in the anterior antennz of the female, seven joints in the second maxilliped, and three joints in the inner branch of the first feet. The abdomen is three-jointed in the female, five-jointed in the adult male. The last segment of the thorax is distinct in the female, but in the male its median part is suppressed in dorsal view, only the lateral lobes having a joint-line, as in Labidocera kroyeri # Giesbrecht. 1C. O. Esterly: The Pelagic Copepoda of the San Diego Region. Univ. of California Publications, Zoology, Vol. 2, No. 4, October 14, 1905, p. 177. 2J. P. McMurrich: op. cit. 1916, pp. 82-87, f. 8-14. Marine Copepoda 17K Length of female 3-6 mm., of male 3:09 mm. The rostral processes are long and acute in both sexes, in the young as well as in the adult (Fig. 14). Some- times, as seen specially in the male, the left rostral hook is smaller than the right. ees _. Fig. 14. Paralabidocera. Front with right eye and rostral hooks of female. The lateral lobes of the last thoracic segment are symmetrical in the female; they are broadly rounded, with a small protuberance at the middle of the lateral aoa or this may be worn down so that the lateral lobe appears evenly rounded ig. 15). 7 ) Fig. 15. Paralabidocera. Hind-body of female from above; sp. Spermatophore. In the male, the latera! lobes are very unequal, that on the left side resem- bling the female, though less broadly rounded in side view, sometimes triangular Fig. 16. Paralabidocera. Hind-body of the male from above. Fig. 17. Paralabidocera. Urosome of female in side view. and pointed. The right lateral lobe is drawn out into a long spike nearly or quite reaching to the end of the second segment of the urosome (Fig. 16). 69085—2 18k Canadian Arctic Expedition, 1913-18 The genital segment of the male (Fig. 16) exhibits a small lobe and notch on the left side. The genital segment of the female (Fig. 15) carries a large wing-like lobe on the left side, terminating in a recurved hook; this hook is easily lost, so that the lobe then appears toend bluntly. In side view the segment presents a ventral convexity and two small curved hooks, right and left of the genital opening (Fig. 17). The anterior antennz of the female reach to the end of the forebody. Of the 24 segments of which they are composed, numbers 3 to 8 are short and subequal; the antenna breaks readily between the 8th and 9th joints. The right grasping antenna of the male, with the geniculation between the 18th and 19th joints, is more like that of Pontella than that of Labzdocera (Fig. 18). Fig. 18. Paralabidocera. Terminal portion of right antenna of male. There is a serrated upraised flange upon joint 17, a serrated border upon joint 18, and two toothed edges upon the compound joint 19-21, namely, a long proximal and a short distal comb. The terminal part of the appendage, beyond the bend, consists of three distinct segments, corresponding respectively to joints 19-21, 22-23 and 24-25. This is a generic character, inasmuch as the right anterior antenna of the male Labidocera has four terminal segments, hat of Pontella two. In the second or posterior antennae, B2 is fused with Ri 1, the zone of fusion being indicated by a shallow impression at the level of the insertion of a group of two si; measuring Ri from this point, the two rami are subequal in length. Fig. 19. Paralabidocera. Second maxilliped. _ In the seven-jointed second maxilliped (Fig. 19), the inner margin of B2 is denticulated as in Labidocera; distally this joint carries two long setae and Marine Copepoda 19k one additional shorter seta; Ri 1 has two sete, Ri 2 has one, Ri 3 has one, Ri 4 has one, and Ri 5 has three apical setae. The distal lobe of B1 has one long seta and two very small anterior setae at its base, one of which was distinctly plumose. In the example figured, one of the two setae of the middle lobe of B1 is lost, its place being indicated by a small mamelon. The distribution of the setae on the swimming legs agrees with Labidocera, the external setae being set in deep notches. In the fifth legs of the female (Fig. 20), it is to be noted that the right and left B1 are confluent across the middle line; B2 has two sete on its hinder surface, one of which is minute. Fig. 20. Paralabidocera. Fifth legs of female from behind. In the adult male the right foot ends in a rounded chela (Figs. 21 and 22); in one case it was observed that the chela was firmly grasping the right anterior 23, Fig. 21. Paralabidocera. Fifth feet of male. Fig. 22. Paralabidocera. Chela of right leg. Fig. 23. Paralabidocera. Left B2. _ Fig. 24. Paralabidocera, Left end-joint. antenna of the same individual, which it had presumably caught hold of in he death-struggle. A lobe on the left B2 (Fig. 21) is directed towards a cor- 69085—23 . 20k Canadian Arctic Expedition, 1913-18 responding tuberosity on the right B1; when the left B2 is disarticulated and viewed from the side, the lobe appears as the proximal end of an elevated border (Fig. 23). On the anterior surface of the terminal joint of the left foot there is an elongate depression beset with groups of very fine hairs, with a small se beside it (Fig. 24). The mandible has five teeth followed by a group of small setz; the first (ventral) tooth is large. The rostral eye has no lens. 15. Acartia clausi Giesbrecht. Station 17 (Table XI), station 18 (Table J), station 20a (Table IX), station 21 (Table II), station 25 (Table III). Station 20h: Port Clarence bay, Alaska, water depth three fathoms, net number 3, surface-tow five minutes, amongst seaweed, August 4, 1913. A small vial contained a number of Cladocera (Podon leuckarti and Evadne nordmanni), a young Caprella, and several Acartia clausi, male and female. The arrangement of the sete on the swimming legs agrees with the description given by Giesbrecht, and the first basal joint (B1) of the second to the fourth feet has an emarginate outer border and an incised inner border as in the type. Station 25, off Cooper Island, near Point Barrow, is the only station within the Arctic Circle where this species was taken, although station 21 lies north of Bering strait. Port Clarence lies to the south of the strait, about 65° north latitude. Sars (1903) has never met with A. clawst in any samples of plankton from the Arctic Ocean. On the south and west coasts of Norway it is as common as A. longiremis with which it is often found. This species is more of an estuarine and inshore form than is A. longiremis. 16. Acartia longiremis (Lilljeborg, 1853). This is an Arctic species with a wide southern extension. Station 6b. 56° 26’N., 133° 00’W., just below the surface, 15 minutes, net No. 4, June 24, 1913. This was a thin Acartia plankton, numbers of A. longire- mis being noted and, in addition, two male Cumaceans and several Ostracods. Station 12b,c. 54° 38’N., 157° 45’W., two surface tows of five minutes each, net number 3, June 30, 1913. A few A. longiremis 7 and g were taken, together with a trace of Oithona and a number of young Amphipoda-Hyperidea. Station 13 a, b,c. 54°30’N., 159° 42’W., three surface tows of five minutes each, net number 8, July 1, 1913. The catch was very scanty but there was a male longiremis, 1-12 mm. in length; the number of sete on the inner border of the two-jointed inner branch of the fourth foot (p. 4 Ri Si) is 3, 5, the same as in A. clausi; Sars figures 2, 5. Station 17 a, b, c. Table XI. Whereas most Calanoids are largely dif- ferentiated by male characters, Acartia is an exception, and the males of A. claust and longiremis are hard to distinguish, if the thorns are lost from the last thoracic segment. Station 18: See under Calanus finmarchicus and remarks on table I. Station 19 a-e. 63° 43/N., 165° 24’W., surface, July 8, 1913, net number 3, five tows of fifteen minutes each. Nearly fifty Acartia identified in part as longiremis, about half as many young Paralabidocera, and a single male Eurytemora herdmant. Station 21 a, b, c, and d, e, f. Tables II and XII. Station 25 b, c. Table ITI. Station 36. Off cape Lyon, Darnley bay, Northwest Territories, net number 4, surface tow of five minutes, August 23, 1914. Five males in company with Eurytemora herdmani (q. v.). Phytoplankton was represented by Ceratium, Chaetoceras and Coscinodiscus. Marine Copepoda 21 Station 40r. Bernard harbour (outer harbour), Northwest Territories, water depth 10 fathoms, three vertical hauls 0 to 5 fathoms through hole in ice, net number 8, temperature —0-8°C., July 1, 1915. Coscinodiscus and Balanus nauplii were abundant. The copepods present were: Acartia lon- giremis 9, Otthona similis ¢, Ectinosoma neglectum and Idyea furcata ¢. Station 42y. Table X. Station 422. See under Pseudocalanus. Station 43e. Table VII. A female carried two spermatophores. 17. Acartia tumida, n. sp. Three examples of a third species of Acartia were taken in surface, at stations 13 a, b, c, in company with Calanus tonsus (q. v.) and Acartia longiremis: (q. v.). The position was 54° 30’ N., 159° 42’ W., July 1, 1918, net number 3. Length of female, 2-00 mm.; anterior antenne not exceeding length of forebody, reaching as far as the front part of the genital segment when laid back, having about the same relative length as in A. bifilosa. Rostral filaments are present, widely separated in ventral view; labrum large trilobate with ciliate edges, as figured by Sars for A. longiremis. Lateral borders of last thoracic segment smooth (Fig. 25); urosome smooth, some minute points dorsally near the posterior edge of the genital segment and at posterior edge of the pre-anal segment; anterior antenne without thorns. The caudal sete (Fig. 26) were broken, some of their swollen basal parts remaining attached to the short and broad rami. 26 Fig. 25. Acartia tumida: end of thorax and the urosome in side view. Fig. 26. Same. Urosome from below. In the swimming feet, the terminal seta (st) of the outer ramus is much longer than Re 3, longer in fact than the whole Re, with a strongly serrated outer edge; the arrangement of the setz is the same as in A. clausv. Fig. 27. Acartia tumida. Fifth legs of female, shown complete on one side, the basal joints parallel. Fifth legs (p 5 ¢): the basal joints, right and left, are parallel; the terminal joint, representing the Re, has a swollen proximal portion followed by a narrow 22K Canadian Arctic Expedition, 1918-18 neck, upon the distal part of which there commence two rows of small denticu- lations pointing distally. These denticulations are evenly disposed, increasing slightly and then diminishing in size, to be continued upon the proximal half of the attenuating setiform process (Fig. 27). This delicate and regular serru- lation is quite different from the coarse denticulation figured for Acartia tonsa, where the teeth are few in number, the proximal largest. 18. Tortanus discaudatus (I. C. Thompson and A. Scott, 1898). In Professor Herdman’s traverses of the Atlantic, which have been referred to under Eurytemora herdmani, he obtained another leading component of the Gulf of St. Lawrence copepod plankton, namely, the present species. Whilst in America he paid a visit to Puget Sound, where he carried out some dredging and tow-netting. Amongst the more abundant forms in the Puget Sound gatherings was this same species, new for the Atlantic and new for the Pacific. It composes 50-75 per cent of the summer copepod plankton off Souris, Prince pens Island, and is very abundant off the Biological Station at St. Andrews, N.B. Station 17 a,b,c. See Table XI. Station 18. See Table I. Station 20a. See Table IX. B. Cyctoporpa, Etc. 19, Oithona similis Claus, 1866. This small and slender species is apt to escape through the meshes of ordinary tow-nets, but none the less it appears frequently in Mr. Johansen’s gatherings. Like Acartia longiremis, it is an Arctic form with a southern ex- tension. Station 12 b,c. See under Acartia longiremis. Station 12d. Same position, surface, 15 minutes, net number 4, June 30, 1913. Phytoplankton (Coscinodiscus, Peridintwm, Rhizosolenia, chain alge), Tintinnoids and Oithona. Station 21 a,b,c. Table IT. Station 25 b,c. Table III. Station 27y 2. Table V. Station 29g 4. See under Huchaeta norvegica. Station 30a. Table VIII. Station 40 c. Bernard harbour, Dolphin and Union strait, water depth 9 fathoms, three vertical hauls, 0 to 3 fathoms, through hole in ice; net number 3, June 7, 1915. Taste XIII (Sra. 40c). Pseudocalanus elongatus, immature ?. Oithona similis a. Cyclopina schneidert. Harpacticus superflexus 3. Dactylopusia signata ? . Station 40d. Same locality, depth, and net, six vertical hauls through hole in ice, 0 to 5 fathoms, June 8, 1915. 1W. A. Herdman, I. C. Thompson, Andrew Scott: On the plankton collected continuously during two traverses of the North Atlantic in the summer of 1897; with descriptions of new species of Copepoda; and an Appendix on dredging in Puget Sound. Trans. Liverpool Biol. Soc. XII, pp. 33-90, pls. V-VIII, Liverpool 1898. Marine Copepoda 23 K Taste XIV (Sta. 40d). Pseudocalanus elongatus 2 . Pseudocalanus elongatus 7 stage V. Eurytemora herdmani? (1-4 mm.). Oithona similis. Cyclopina schneideri. Ectinosoma neglectum. Harpacticus superflecus ? (1-05 mm.). Dactylopusia signata. Station 40e. Same locality, depth, and net, three vertical hauls, 5-0 fathoms, June 10, 1915. Several Oithona similis with Dactylopusia and Ectino- soma neglectum. Station 40r. See under Acartia longiremis. A female Oithona measured 0-86 mm., a male 0-78 mm. The relative lengths of the last thoracic segment, the abdominal segments and the furca were:— . Th5. Abl. Ab2. Abs. Ab4. Ab5. = Furca. Male.... 7 10 8 7 7 7 7 Female. . 8 19 9 8 9 7 . Station 41s. See Table VI. Station 42p. See under Pseudocalanus. Station 42y. Table X. Station 43e. Table VII. Station 46b. Bernard harbour, depth 6 fathoms, ice 5 feet thick, vertical haul with net number 3, from bottom to surface, temperature 29-2° F., Febru- ary 5, 1916. About half a dozen Copepods in all, including: Octhona similis, Oncaea conifera, Idyea furcata, and Dactylopusia signata. Station 46h. Dolphin and Union strait, off Chantry island, depth about 50 feet, ice 4 feet thick, three vertical hauls, with net number 3, from 33 feet to surface, June 10, 1916. Several Oithona, with several immature I dycea furcata and one Cyclopina schneideri 9. 20. Cyclopina schneideri T. Scott, 1903. Thomas Scott: Notes on some Copepoda from the Arctic Seas collected in 1890 by the Rev. Canon A. M. Norman, F.R.S., Ann. Nat. Hist. (7) XI, 1903, p. 6. Station 40c. See Table XIII. Station 40d. Table XIV. Station 41g. Bernard harbour (outer harbour), depth 0-2 fathoms, surface 5 minutes, net number 3, August 1, 1915. Taste XV (Sta. 41g). Eurytemora herdmani, one female. Cyclopina schneideri, one male, one female. Harpacticus uniremis, one (injured). ' ; Harpacticus superflecus, 48 examples, including several males and one female with ovisac. Station 46h. See under Oithona. A female from this station measured 0-84 mm., caudal rami shorter than anal segment as 5:6; length of caudal ramus to breadth as 5:3; interrelations of caudal sete asin C’. litoralis Brady. Anterior antennz 12-jointed, with six terminal subequal small joints; of the proximal joints the fourth is the shortest, the sixth the longest, agreeing with Scott’s figures and thus establishing the constancy of these proportions. The mandible, also figured by Scott, has a large B2 (the basal joint of the palp), shaped like an ascidian, carrying at the summit an outwardly curved two-jointed Ri, which is separated by a wide concave interval from the four-jointed Re. 1W. Giesbrecht: Die litoralen Cyclopiden des Golfes von Neapel. Mitth. zool. Stat. Neapel 14, 1901 .pp. 40-46. 24K Canadian Arctic Expedition, 1918-18 The fifth legs (Fig. 28) are two-jointed, the second joint carrying three setz at the end, a slender one in the middle, a stout vaned (bilimbate) se and a similar but smaller si; the proximal joint carries a simple se, like the apical seta. 28 Fig. 28. Cyclopina schneidert. Fifth leg of female. The male, from station 41g, was nearly 0-74 mm. long. Anterior antenne two-thirds the length of the forebody, with 16 joints; joints 4 to 9 inclusive are telescoped, 10 to 14 inclusive form the intumescence; the 10th joint carries two spiniform processes applied to the anterior face of the 11th; the remaining segments of the enlarged part with pectiniform sete. 21. Oncaea conifera Giesbrecht, 1891. For reference see Nordisches Plankton, Bd. IV, Lief. VIII, Copepoden by Dr. van Breemen, p. 188-9, Kiel und Leipzig, 1908. Station 30a. See Table VIII. Station 42y. Table X. Station 42z. See under Pseudocalanus. A single female preserved from this station measured 0-65 mm. in length. Station 466. See under Oithona. This is an Arctic species with an exceed- ingly wide southerly range even reaching to the Antarctic ocean. Or it might perhaps be described as a Mediterranean species, ranging north, south, east and west from its centre of distribution. It cannot be stated positively whether it is an Arctic emigrant to the south or a Mediterranean migrant to the north. The evidence from the present collection bearing upon this point is not very cogent, but, so far as it goes, it points to the north as the home of this species. What is true of the distribution of Oncaea conifera applies also to Oithona similis, except that the latter, like Acartia longiremis, penetrates into the Baltic, from which sea Oncea conifera appears to be excluded. C. HARPACTICOIDA. 22. Ectinosoma neglectum Sars, 1904. G. O. Sars: Crustacea of Norway. Copepoda-Harpacticoida, Bergen, 1904, p. 31. Station 40d. See Table NIV. Station 40e. See under Oithona. Station 40r. See under Acartia longiremis. An immature female from station 40r was 1-07 mm. long; the distal joints of the fifth legs were not separated from the rest of the lamelliform ap- pendage, but the marginal setee were present and elongated. The inner and Marine Copepoda 25 K outer branches of the fourth legs were 3-jointed and equal., : Anterior antenne with five joints; in the figure of the antenna most of the sete are omitted; on the terminal joint one of the setz has a swollen base (Fig. 29). y:. Fig. 29. Ectinosoma neglectum@ juv. Front and anterior antenna. The anterior lip (labrum) projects in front of the mouth-parts as an acute recurved hook in both sexes. Two males, from station 40e, measured 0-77 and 0-86 mm. respectively. On the ventral side, the posterior borders of the ab- dominal segments are fringed with delicate spinules, including the pre-anal and anal segments, on which the spinules are smaller. On the dorsal aspect, the posterior borders of Ab 1, Ab2, Ab3, and Ab4 are conspicuously fringed. The urosome of the male consists of six segments: Th 5 and Ab 1-5. The anterior antenne of the male (Fig. 30) are thick and short, with a double protuberance at the back of the third joint. This protuberance is shown as a single tubercle in the figure by Sars. Fig. 30. Ectinosoma neglectum. Anterior antenna of male, from below. The posterior antenne resemble those of E. sarsi; the Re is 3-jointed with the following relative lengths of the joints: 6, 4, 11; Re 1 carries a distal seta, Re 2. a stronger and longer seta, Re 3 a short setula and two terminal plumose sete, one longer than the other. The mandibular palp likewise resembles that ‘of E. sarsi: a long B2, with a distal group of three sete, carries a terminal one-jointed Re and, at a distance from the latter, a shorter tri-setose Ri. 26 K Canadian Arctic Expedition, 1913-18 The caudal furca is as long as the anal segment (Fig. 31): there is a short . strong spine on the outer margin of each ramus and, more distally, a grour of two slender auxiliary sete. Fig. 31. Ectinosoma neglectum 3. Left ramus of caudal furca from above. Fifth feet (p. 5 #) have the marginal spines not exactly with the same interrelative lengths as figured for the type by Sars, but the anterior or appen- dicular seta arises from the distal joint near the base as in the original (Fig. 32). 32. sania On Ths PTL MLO ah2z ra HU y I pee / my wot UA tetsu Fig. 32. Ectinosoma neglectum. Fifth feet with part of urosome. Swimming feet (pl-p4) show some variation in arrangement of sete in different individuals and even on the two sides of one. All the Ri 3 have five sete (1 se 4 si); p1 Re 3 has six sete, asin EF. sarsi (3 se, 1 st, 2 si); p 2 Re 3 has seven sete (3 se, 1 st, 3 si) instead of eight in E. sarsi; p 3 Re 3 has eight sete (3 se, 1 st, 4 si); in two specimens the proximal se of p 3 Re 3 was absent on one side, in another the full number occurred on both sides; p 4 Re 3 has seven sete (2 se, 1 st, 4 si). 23. Ectinosoma finmarchicum (T. Scott, 1903.) Station 27 t, wu. See Table IV. Female of 1-07 mm., carrying a yellow ovisac in the preserved state. An- terior antenne 6-jointed; p 2 Re 3 with seven sete as in EF. neglectum. Upper lip bluntly rounded. The fifth legs have the inner seta of the lamellar process. and the middle seta of the distal lobe equal and longer than the rest (Fig. 33). The appendicular seta arises from the distal lobe near the base, whereas in Marine Copepoda 27K Scott’s figure (op. cit. pl. 1, f. 18), it is shown arising from the basal joint. The inner lamellar process and the distal lobe of p 5 are elongate and subequal. The caudal sete reached a length of 0-64 mm. 33. Fig. 33. Ectinosoma finmarchicum. Fifth foot of female. Sars cites E. finmarchicum as a doubtful synonym of E. elongatum, adding that the latter is of smaller size, 0-88 mm. He figures the appendicular seta of the distal lobe of p 5 in E. elongatum as arising not far from the distal margin of the lobe. 24. Pseudobradya minor (T. and A. Scott, 1896). Station 41n. Bernard harbour (inner harbour), depth 0-2 fathoms, surface 5 minutes, net number 3, August 9, 1915. Associated with Harpacticus superflexus (see below). Length of female 0-664 mm., caudal sete2 0-178 mm. Anal segment and caudal ramus form a simple cone in side view, the ramus appearing slightly 34. Fig. 34. Pseudobradya minor. Anterior antenna of female. shorter than the anal segment as 5: 6. Anterior antenne (Fig. 34) 6-jointed, proximal parts expanded. Posterior antenne with 3-jointed Re, the pro- portional lengths of the joints being 2, 1, 9. First and second maxillipeds are shown in their relative positions in Fig. 35. The first maxilliped (mp 1) is stout and curved, the two proximal joints subequal 28 K Canadian Arctic Expedition, 1918-18 in length. The second maxilliped (mp 2) is short and straight, with very long plumose basal seta, about twice the length of the appendage. Fig. 35. Pseudobradya minor. First and second maxillipeds. The arrangement of sete on the thoracic legs is the same as that indicated for the two before-named species of Ectinosoma; in particular p 2 Re 3 has seven sete (Fig. 36). TS se Fig. 36. Pseudobradya minor. P 2 Re 3. The outer margin is below. In the third foot (p 3) the basal joints (B1 and B2) are broad, and the rami are inserted upon the outer half of B2, so that the right and left Ri are Fig. 37. Pseudobradya minor. Part of third foot, anterior surface. widely separated; B2 has an se, and rows of spinules at the bases of the rami and around the inner angle; B1 has a distal marginal anterior row of spinules interrupted in the middle of the series (Fig. 37). Marine Copepoda 29K The fifth foot resembles that of the type, but the marginal setz are uni- formly longer than in the figure by Sars (Fig. 38). Fig. 38. Pseudobradya minor. Fifth foot of female. The form here described differs slightly from the typical Ps. minor in certain proportions, somewhat as Ectinosoma neglectum differs from E. sarst. In the gathering from station 27 t, u, (see remarks under Table IV) there was another Pseudobradya, of 0-86 mm., caudal sete 0-51 mm., which may be the Ps. acuta of Sars. It comes very near to Ps. acuta by its rostrum, p 5, and furca; but in p 5 the appendicular seta arises near the base of the distal joint, whereas in acuta Sars describes and figures it as issuing from the basal joint. In Ps. minor Sars mentions the caudal sete ‘‘not much elongated”. In Ps. acuta the caudal sete are “‘slender and elongated”. Sars obtained only two examples of Ps. acuta, in company with Ps. minor, at Selven, Trondhjem Fiord. A similar origin of the appendicular seta from the basal joint was figured by T. Scott for Ectinosoma finmarchicum, wherein this species would differ from EF. elongatum Sars, which was also found only at Selven in 3-6 fathoms, on muddy sand. The value of the appendicular seta as a diagnostic feature seems not to be fully established. 25. Harpacticus superflexus, n. sp. This species resembles H. flerus Brady in all but size and the shape of the finger of the posterior maxilliped. Station 25b, c. See Table III.’ Immature. Station 30a. Table VIII. Immature 2. Station 40c. Table XIII ¢ Station 40d. Table XIV. 21-05 mm. Station 41g. Table XV. 48 examples. Station 41n. See under Pseudobradya. Length of female, 1-20 to 1-26 mm., of male, 1-04 to 1-12 mm.; caudal furea a little longer than anal segment, caudal sete, 0-65 to 0-69 mm., some- times shorter in the male. Urosome stout, barrel-shaped; caudal rami parallel, as broad as long, spinose distally. The body in the preserved state is often transparent. The cephalosome has a polished convex dorsal surface; the remaining segments of the thorax are smooth, with a metallic lustre, and groups of small dark spots on the pleure. 30K Canadian Arctic Expedition, 1913-18 Anterior antenne 9-jointed, seven-tenths the length of the cephalosome measured in the middle line. Posterior antennz with Re two-jointed (Fig. 39); the number and arrangement of sete is subject to variation, as is the relative length of the two joints. 34. Fig. 39. Harpacticus superflerus. Base of posterior antenna showing the two-jointed Re. The mandible has the structure shown in Fig. 40, both rami of the palp being one-jointed; the outer ramus is the smaller; on the other mandible of this individual instead of the two si of Ri shown in the figure, there was a group of three sete as in Tigriopus (Sars). Fig. 40. Harpacticus superflecus. Mandible. The maxilla was like that of H. chelifer, with two long plumose sete behind the masticatory claws on B 1, as figured by Sars; below the claws (observed in the male) were two subequal sets with distended proximal portions and long-plumed attenuated distal portions; B2 bifid, the proximal inner smaller lobe carrying two equal plumose sete, the upper larger lobe, a group of sete; Riand Re both tri-setose. First maxilliped (mp 1): B 1 with three setigerous digitiform inner lobes (Li); B 2 is the distal digitiform segment of the appendage, carrying a sub- Fig. 41. Harpacticus superflecus. Terminal portion of first maxilliped. distal group of four setze and terminating in the claw or dactylus of the appen- dage; above the claw, and parallel with it, there is a plumose seta, and another smaller seta below it (Fig. 41). Marine Copepoda 31k Second maxilliped (mp 2): like that of H. flexus, with simple fusiform hand, but the dactylus is shorter than the hand as 2: 3 (fig. 42). 42. | Fig. 42. Harpacticus superflecus. Second maxilliped. The first thoracic foot (p 1) is like that of H. flerus, both rami two-jointed, Ri about as long as the proximal joint of Re; Ri 2 with a claw-like spine and two sete at the end, Ri 1 with distally placed si (Fig. 43); Re 2 ending with three curved claws and a slender seta. In the second thoracic foot (p 2 ¢) it is to be noted that the middle joint of the inner ramus (Ri 2) has two si, against one si figured for H. chelifer; this duplication of the si was found in two successive preparations on both sides. The third and fourth legs agree with H. chelifer. 43. Fig. 48. Harpacticus superflexus. Terminal portion of inner ramus of p 1. In the male, the second foot (p 2) has the mucronate process of Ri2 only a little exceeding the length of Ri3 (Fig. 44). 44. Fig. 44. Harpacticus superflecus. P 2 Ri of male. In the third foot of the male (p 3), Re 1 is two-thirds the length of Re 2 and Re 3 together, the relative lengths of these joints being'26, 19, 20; the enlarged outer spines of Re 8 are graded as 10, 17, 27; thus Re 3 se 3 is to Re 3 as 27 : 20, the se 3 has usurped the position of the terminal seta (st), so much so that the latter appears to belong to the series of si, of which there are four (in addition to the st); the st has about twice the bulk of the fourth si, but it is flexible, longer and much slenderer than the se3. In H. chelifera the p3 Re 3 st is rudimentary; in H. uniremis a it makes a fourth spine. In H. gracilis a the st is like that of H. uniremis, but the Se 3 is the shortest of the series. The male of H. flexus is undescribed. 32K Canadian Arctic Expedition, 1913-18 Fifth legs of female (p 5 ¢): inner lamellar process low, broad, evenly arched, with four marginal spines; distal joint with five marginal spines (Fig. 45). Fig. 45. Harpacticus superflecus. Fifth legs of female. Fifth legs of male (p 5.7): inner lamellar process absent as in H. uniremis; an arcuate row of spinules occurs on the segment (Th 5) to the outer side of p 5; in front of this arc there is a transverse row of points, and a corresponding oblique row occurs on the genital segment (Fig. 46). Fig. 46. Harpacticus superflexus. Fifth leg of male with adjacent segments. With reference to the pelagic occurrence of this species, it may be mentioned that Brady (Brit. Cop. 1880, II, p. 152) records that H. flerus had been taken by the surface net in Westport Bay, Ireland; elsewhere at the bottom in depths of 1 to 20 fathoms. ne The anterior antenne of the male present the distal expansion found in other species of Harpacticus; when viewed from the outer aspect the dactylus is seen to possess a lateral spur and tubercle. 26. Harpacticus uniremis Kréyer. Station 7a. 55°42’N., 136° 20’ W., surface 5 minutes, net number 3, June 25, 1913. Seventeen examples. One female measured 1-4 mm., one male 1-28 mm., another male 0:80 mm. In addition, there were young Gammaridea and an Ostracod (Conchoecia). Station 13. 54°30’ N., 159° 42’ W. Several surface gatherings, with net number 3, July 1, 1913. There were some Cypris larve of Cirripedes. Marine Copepoda 33 Kk TasiE XVI (Sta. 18). Calanus tonsus. Three, immature. Pseudocalanus elongatus?. One. Metridia lucens#. One. Acartia longiremis? and?. Five. Acartia tumida@. Three. Harpacticus uniremis3 and@. Eleven. One female bearing ovisac was 1-20 mm. long, caudal sete 0-80 mm. ; anterior antenne 9-jointed; p 1 with four biserrulate claws at end of Re and one such claw at end of Ri. The terminal claw on p 1 Ri is accompanied by a falci- form seta, which is often broken quite regularly at one spot. appearing as if jointed (Fig. 47). Fig. 47. H.uniremis3. Terminal portion of p 1 Ri; from station 13. The maxilla is like that of H. chelifer; B2 bifid, the rami one-jointed, Ri trisetose, Re quadrisetose, the masticatory sete vaned (Fig. 48). Fig. 48. H. uniremis. Maxilla. Station 50d. Second maxilliped: B 2 with a proximal comb of spinules on its anterior face (Fig. 49) and two combs on its posterior face, one proximal and one central, as figured by Sars. ; Station 14. See under Paralabidocera. One ovigerous female, length 0-96 mm. Station 41g. Table XV. One example of 1-36 mm. 69085—3 34k Canadian Arctic Expedition, 1913-18 Station 42p. See under Pseudocalanus. Several examples comprising males and females. Length of one male 1-2 mm. When the body is viewed from the side, without further preparation, it can be observed that the ectal spinules or spinules on the outer surface of Re 1 in p2—-p4 are arranged in three oblique rows: = Fig. 49. H. uniremis. First pair of legs and second maxilliped (of right side) in position. Station 50d. this is indicated in a figure by Sars. The anterior antenne of the male present a distal expansion followed by a movable finger (dactylus) which is furnished with a smooth spur projecting forwards, as described and figured by Sars; in certain aspects the spur looks like the main body of the joint. Station 50d. Young point, Dolphin and Union strait, Northwest Territories, in beach water amongst alge, July 21, 1916. There were three Harpacticoids in the vial, one Idywa furcata, and two H. uniremis ¢. One female carried an ovisac, and there was a loose ovisac in addition; length of 2, 1-3 mm. In the thoracic legs, p 2 Ri2 has two si; p5 with 4 marginal spines on the inner expansion and 5 on the distal lobe. Sars finds that the H. chelifer var. arcticus described from Bering Sea on floating kelp by 8. A. Poppe (Arch. f. Naturgesch. 50, 1884) belongs to H. uniremis. According to the same author, it is found along the whole Norwegian coast, but only in depths of 20 to 100 fathoms. L. W. Williams found it in Narragansett Bay abundant in tow-nettings in shallow water,! and I have found it amongst the stomach contents of the winter flounder at St. Andrews, N.B. It has not been taken at Woods Hole.? 27. Idyzea furcata (Baird). Station 20a. See Table IX. One female. Station 40r. See under Acartia longiremis. Several females, one with ovisac, 1:03 mm., another 1-00 mm., another 0-80 mm., and a fourth 1-05mm.: relative lengths of Th 5, Ab 1-4, and furca: 10, 15, 10, 9, 8, 6. The first and second maxillipeds when seen in situ appear much alike, uncinate; the anterior with larger claw, biarticulate; the posterior, three jointed, the claw itself having an intercalary joint at its base. Station 41s. See Table VI. 11, W. Williams: Notes on marine Copepoda of Rhode Island. Amer. Nat. 40, p. 653-4, 1906. ‘R.W. Sharpe: Copepoda of Woods Hole. Proc. U.S. Nat. Mus. 38, pp. 405-436, 1910. Marine Copepoda 35K Station 42p. See under Pseuducalanus for position. Tasie XVII (Stra. 427). Pseudocalanus elongatus. One?. Eurytemora herdmani. Oneo. Oithona similis. Four. Harpacticus uniremis. Seven (f and ¢). Idyea furcata. Two?. Danielssenia stefanssoni. Five females. Length of one ¢, 1-2 mm., anterior antenna 8-jointed; sete with penicillate tips on p 1 Re 3, p1 Re2, and p1 Ri3. Station 42y. See Table X. Station 422. Dolphin and Union strait, off Bernard harbour, depth 17 feet, ice 2 feet thick, midnight, water temperature 29-2° F., three vertical hauls bottom to surface, December 12, 1915. Taste XVIII (Sta. 422). Pseudocalanus elongatus, males and females. Metridia longa, young (2-jointed urosome). Acartia longiremis. Oncea conifera, one female. Idyea furcata, many young and adult. There was a female with ovisac containing eggs in the first nauplius stage. One male measure 0:88 mm. In immature Idyea furcata both the apical claws of p 1 Ri3 were observed to be penicillate; in the adult only the longer of the two is penicillate. Station 46b. See under Oithona. Station 46h. See under Ozthona. Several immature examples. Station 50d. See under Harpacticus wniremis. A single female with ovisac; length 1-13 mm. I have also found this species very abundant in the stomach contents of the winter flounder at St. Andrews, N.B., associated with Harpacticus uniremis. 28. Dactylopusia signata, n. sp. Station 40c, d,e. See under Ovthona. Station 41n. Bernard Harbour, Northwest Territories, depth 0-2 fathoms, August 9, 1915; associated with Harpacticus superflerus, Amphiascus nasutus, and Danielssenia stefanssonv. Length of one female 0-8 mm., of another 0-63 mm. None was found with ovisac and no male was observed. Rostrum blunt, conspicuous in side view. Caudal rami very small, shorter than the anal segment, the innermost 50, Fig. 50. Dactylopusia signata. Anal segment, caudal ramus and sete. but one of the terminal sete on each ramus with a characteristic rounded pro- tuberance.near the base on the inner side. This ental protuberance of the caudal seta is the chief distinctive mark, to which the specific name refers (Fig. 50). 69085—33 36 K Canadian Arctic Expedition, 1913-18 Anterior antenne 9-jointed, the 8th joint very small and a constant char- acteristic (Fig. 51). Mouth-parts normal; the first maxilliped is clawed like the second, its claw being longer and more powerful than that of mp 2; the basal joint of mp 1 has three inner setigerous lobes of which the proximal was observed with a single long thick soft seta, the other two having more than one seta at their apices. - St. Fig. 51. Dactylopusia signata. Anterior antenna. The first thoracic legs are like those of D. thisboides and D. neglecta; Ri 1 with a plumose si at the centre of the joint. The outer distal angles of Re 1 and 2 of the natatory legs are not conspicuously produced, as they are in D. thisboides. Second legs with sete as in D. thisboides; the ectal spinules of Re are coarser than those of Ri; B2 with slender se and triangular acute ental spur, a feature also found in D. thisboides; in p2 Ri2 the slender proximal si arises distad of the centre of the joint. Third legs: B2 with still slenderer se and very small ental spur. In the fourth legs the Ri 2 has only one si and this appears to be distinctive. In the natatory legs p 2 to p 4 the terminal seta of the outer ramus is longer than the entire ramus, in p 4 much longer. The se 3 has the same length as the Re 3 in p 2 and p 4, a little shorter than the Re 3 in p3. The fifth legs appear to differ from D. thisboides in the interrelative lengths er the marginal spines, but the general correspondence is remarkably close Fig. 52). Fig. 52. Dactylopusia signata. Fifth leg. It might be supposed that this species may be a submature “instar ”’ of D. thisboides, but the structure of the first antenne is hard to reconcile with such a supposition. A word must also be said about the character of the caudal seta, which seems at the surface to offer an unequivocal distinction. On consulting Claus’s work on the free-living Copepods (Leipzig, 1863) at a distance from my material, I found an exactly similar condition of the sete figured for Thalestris forficula Claus. This species is now placed by Sars in a new genus, Microthalestris, and nothing is said about the ‘‘ kolbig angeschwollen ”’ bases of Marine Copepoda 37K the caudal setz, although a figure by Sars shows them slightly enlarged. A similar condition, again, still more pronounced, is figured by Sars for Amphiascus giesbrechti, but here the protuberance is directed outwards. Whatever may be the significance of this small tubercle on the caudal sete, it is of some interest to find it occurring in three different genera. 29. Amphiascus nasutus (Boeck). Station 41n. See under Dactylopusia signata. Station 43e. See Table VII. This is, for its size, a stout harpacticoid with heavily built cylindrical urosome. Length of female, 1-22 mm., of male, 0-72 mm. Caudal ramus truncate, shorter than anal segment (Fig. 53). Creu Vey UveuY vuuvyeeueNeY reyvuVINWN Fig. 58. Amphiascus nasutus. Anal segment and furea from below. Anterior antenne distinctly 9-jointed, the proportional lengths of the joints being: 7, 5, 5, 7, 2,3, 1-5, 2,4. Posterior antenne with Re three-jointed, the middle joint short; Re 1 with one seta, Re2 achetous, Re3 with one proximal and two strong apical setz with several setules around their bases. Second maxilliped with the si of the hand arising towards the distal end of the joint. Thoracic legs: p1 with both rami three-jointed as in Dactylopusia, but the si of Ri 1 is inserted near the distal end of the joint (Fig. 54). Fig. 54. Amphiascus nasutus. P 1. In the second leg (p 2), Ri2 has two sete, Ri 3 has only four (1 se, 3si), in place of the five in Dactylopusia (Fig. 55); B2 has a slender se and a short thorn- like process in place of an si; outer distal angles of Re 1 and Re 2 are produced 38 K Canadian Arctic Expedition, 1913-18 into two thick-based, somewhat blunt acuminations, that of Re 2 larger than that of Re 1 (Fig. 56). In the fourth leg Ri2 has only one si (Fig. 57); Re3 only seven sete (3 se, 1 st, 3 si). SS. 56. ST. Fig. 55. A. nasulus@. p 2 Ri. Fig. 56. Same. p 2 Re. Fig. 57. Same. p 4 Ri. The fifth legs (p 5 ¢) are highly characteristic, with a long and steep declivity occupied by a few spinules, stretching between the two outermost spines of the distal lobe (Fig. 58). Behind the innermost sete of the inner lobes there is seen a chitinous thickening proceeding backwards from the genital opening. Fig. 58. Amphiascus nasultus. p5@. In the male, the inner ramus of the second foot is transformed in an extra- ordinary manner, as in the type figured by Sars. 30. Tachidius brevicornis Lilljeborg, 1853. Station 40v. Creek mouth at Bernard harbour, Northwest Territories, 0-1 fathom, July 8, 1915. The gathering consisted of seventeen small Harpacticoids, all of this species, all females, and all, with one exception carrying an ovisac. Length 0-76 mm.; eggs counted in five ovisacs: 39, 43, 44, 44,53. Arrange- ment of the sete on the rami of the natatory legs p 1 to p 4 and dorsal crescentic Marine Copepoda 39 K spinulose anal valve as figured by Sars. In the first leg B2 has an ental spine set upon a prominent rounded boss and an equal ectal spine on the anterior surface (Fig. 59). 5g, Fig. 59. Tachidius brevicornis. First leg, anterior surface. 31. Danielssenia fusiformis (Brady). I have identified a single individual of this species from Station 25 6, c, taken at the surface close to ice, north of Cooper island, Alaska, August 27 and 28, 1913.1. The length was about 0-85 mm. As a Danielssenia, its distinguishing feature is the 5-jointed antenna, but in the specimen this is not so decisive as could be desired. The terminal part of the antenna seems at a certain focus to consist of two joints. The antenne carry a number of conspicuous thorny bristles, three of which are especially prominent upon the basal half of the terminal portion and one of them is inserted at the level where the articulation should occur. This bristle was lost on one antenna and its sharply defined broad base of insertion simulated an interarticular junction. The basal seta of the posterior maxilliped was damaged accidentally in the manipulation. The fifth foot accords with the figure by Sars. Neither Brady nor Sars seems to be entirely satisfied as to the distinct- ness of D. typica and D. fusiformis, and the differential characters advanced by Brady are not those upon which Sars relies. ‘32. Danielssenia stefanssoni, n. sp. Station 41n. See under Dactylopusia. Station 41s. See Table VI. Station 42p. Dolphin and Union strait, surface-tow, with net number 3, 10 minutes, Bernard harbour (outer harbour), water depth three fathoms, September 30, 1915. Tasie XIX (Sta. 42p). Pseudocalanis Clongatus’s ocsig cg pace cog ei nesses wave meme Si wa RR Se ees 12 (young and adult). Burytemore herdmMantr..s3c60 9 cx eks ean esi gs kee pany ods ewe 0a HERD 3 (males). OUR ONG SUMALIS 0.5. ccccack orcs ace ad eo ASHE SREE OD AEE RN LRERS wT OAR DEES 4, GP DOCLCUS UNUTETINS s. ccossssssrcniuis-o.naibcdaneeoureundeiihlas Pe GMC e ACLS BEBE ES 11 (males and females). LAY OC PUR COLD iscsi sen ie S8 RES si de a fs Rabat Neb Oa Rate SAN DANN 2 (females). Daniel ssenta: Stefan SSO ais cosesscs x costoce 2 ch tad tev PAIN PA ARDS in ems Se Raa! A a a 5 (females). Length of female, 1-226 mm. Rostrum prominent, defined behind. Caudal rami slightly exceed anal segment as 10:9. Anterior antenne 6-jointed with following relative lengths of joints: 13, 10, 7, 4, 5, 5. Posterior antenne with Vv See Table III. 40 Kk Canadian Arctic Expedition, 1913-18 Re three-jointed; Re 1 carries a small proximal si inserted near the middle of the joint, in addition toits distal plumose si; the distal joint of the Ri carries a long spicate seta followed by three geniculate sete, then, near the inner distal margin three strong spines; between the two subdistal spines of this group there is a long curved claw, not described in other species (Fig. 60). Fig. 60. D. stefanssoni@. Distal joint of inner branch of posterior antenna, viewed from the mesial surface. In the mandible, arising from a point near the middle of the Ri, there is a group of three si instead of two si figured by Sars for D. fusiformis; observed in both sexes. In the maxilla, the small club-shaped Re carries three long plumose sete flaring apart as figured by G. 8. Brady for D. fusiformis. The armature of mp 2 differs from that of D. fusiformis, the two plumose sete of the basal joint being inserted at the same transverse level instead of one behind the other (Fig. 61). Fig. 61. Posterior maxilliped. D. stefanssoni. The thoracic legs of the female offer few distinguishing characters: pa Re 3 has eight sete (3 se, 1 st, 4si); p3 Ri3 has six sete (1 se, 5 si); p4 Re3 Fig. 62, D. stefanssoni9. P3 Ri. has eight set; p 4 Ri3 has five (1se, 4 si). In the third foot (p 3) the outer distal angle of Ri2 is produced into a simple cone in place of the mucronate process of the male (Fig. 62). Marine Copepoda 41x In D. typica, as figured by Sars, and in D. fusiformis, as figured by Brady, the Ri3 of p 4 has four sete, there being only one seta arising from the centre of the inner margin of the joint. In both sexes of D. stefanssoni there are three sete at the apex of p 4 Ri 3, namely a short se and two longer si; on the inner margin of the joint there are two more si, a proximal one arising from the middle of the inner margin, and a distal one inserted between this and the apex of the joint. In D. sibirica Sars, p 4 Ri3 has six sete in the female, five in the male. Fifth legs (p 59): hardly to be distinguished from D. sibirica, unless it is by the interspacing of the marginal spines on the inner lamellar expansion ; differing from D. fusiformis in the more proximal origin of the innermost mar- tinal spine of the inner lamella (Fig. 63). Fig. 63. D. stefanssoni. Fifth leg of female. In one case the distal joint of one side showed an aberration in the presence of along supernumerary spine at the inner side of the lobe, making a total of six marginal spines instead of the normal number, five (Fig. 64). bh. Fig. 64. D. stefanssoni. Aberrant fifth foot of female. In the male, the fifth legs are small, the rounded distal joint with five seta, the reduced inner lobe with two unequal sete, as in D. typica. Description of male; length 1-01 mm.; anterior antennz subcheliform, as im D. typica, figured by Sars. The second thoracic leg (p 2) offers distinctive characters in the presence of a powerful hamate process on the inner side of 42K Canadian Arctic Expedition, 1913-18 Ril, and of a serrulate rostriform process of the reduced Ri3; the subulate process of Ri 2 is a generic character (Fig. 65 and 66). 6s Fig. 65. D. stefanssoni?. P 2 Ri. Fig. 66. Same. P 2 Ri 8 enlarged. In the third leg of the male, Ri2 is produced at its outer distal angle into a strong mucronate process of rather complex form (Fig. 67). In the fourth foot the distal angle of Ri 2 is produced into a slightly curved acuminate pro- cess. Fig. 67. D. stefanssoni a. P3 Ri. The only other species with which the characters of the male D. stefanssoni can be compared is D. sibirica G. O Sars (1898, Jana Expedition op. cit. p. 343). The hamate process on p2 Ri is common to both. On the other hand, in D. sibirica the reduced Ri3 of the second foot of the male is without a rostri- form process. This is the cardinal distinction, the presence in the one and the absence in the other of a sharply defined character. The anterior antenne in the female of D. sibirica are five-jointed. Marine Copepoda 43 K D. MOoNsSTRILLIDAE. 33. Thaumaleus bernardensis, n. sp. Two males were taken at Station 422, December 12, 1915 (see under Pseu- docalanus). Length of one male 1-9 mm., of the other 2-4 mm. The description relates to the larger. The head and first thoracic segment are fused together to form a cephalo- thoracic segment which only slightly exceeds the next three segments (Th 2-4). The lengths of the antennz, of the cephalothorax, and of the three free pedigerous thoracic segments combined, are subequal, the proportions in the order named being: 55 :56;53. The hind-body, comprising the apodous fifth segment (Th. 5), the genital segment, two following segments and the furca, has the relative length represented by the number 35. Thus the forebody is approxi- mately three times the length of the hind-body. The anal or last abdominal segment shows superficial indication of an imperfect division into two segments, the same appearance being presented by both individuals. Counting it as one segment, the caudal furea is a little shorter, in the ratio of 7 to nearly 8. There is a very small papilla on the ventral side of Th. 5, representing a rudiment of the fifth legs (Fig. 68). The ventral lobes of the genital segment have the proportions shown in the figure. Each caudal ramus carries four sete, the most ventral one being much shorter than the others (Fig. 68). Fig. 68. Thaumaleus bernardensis. Hind-body of male. The distance between the frontal margin and the mouth cone is less than one-third of the distance of the latter from the hinder margin of the cephalo- thoracic segment. On the ventral side of the head there are several chitinous structures intervening between the anterior antenne and the rudimentary mouth-cone. In front of the latter the cuticle is wrinkled, as mentioned by Giesbrecht for Th. longispinosus, and the wrinkles terminate in a small papilla, 44x Canadian Arctic Expediiion, 1913-18 which may represent a rudimentary (i.e., vestigial) labrum. In front of this there is another median papilla of uncertain significance, and before this again a pair of clear oval areas. At the base of each anterior antenna there is a small transversely elongate chitinous thickening. Finally, on either side of the supposed labrum there is a wrinkled papilla showing a small central cavity; these are the possible vestiges of posterior antenne (Fig. 69). 64. \ Fig. 69. 7. bernardensis. Ventral side of head. The five antennary joints have the numerical proportions 8, 10, 5, 15, 16. The fifth joint carries a strong, terminal claw-like seta, which can be held for- wards or bent at a right angle to the joint. The following sete are to be found at different points on the antennz :— First joint: a subulate seta with short plumes. Second joint: five shortly plumose subulate sete, of which three are to be seen at the margin (Fig. 69), and in addition a long plumose seta arising dor- sally at the distal margin, whose long plumes occur on the slender distal portion of it. Third joint: two long plumose set and a shorter subulate seta beset with fine points. Fourth joint: sever. sets, including a slender esthetask or sensory filament and one long plumose seta: proximad of the long plumose seta are two marginal subulate setze of which the proximal one is the longer; removed from the mar- gin a little in front of the proximal subulate seta and proximad of the base of the long seta is the esthetask. In Th. longispinosus, Giesbrecht figures the esthetask alongside of the long seta. Distal to the base of the long setais a marginal subulate seta like the proximal one. Exactly opposite the base of the long seta is a short subulate seta, and in front of this a precisely similar one. In Giesbrecht’s figure of Th. longispinosus, in place of the single marginal proximal subulate seta, there are two equal sete side by side. Fifth joint (Fig. 70): there are three branched sete, a long plumose seta, four soft slender setze which look like esthetasks, a marginal and a subterminal subulate seta and the terminal claw, making eleven altogether, as in Th. longi- spinosus. The swimming feet are all alike, both rami three-jointed, the Re with 1. 0, 1 se; 1, 1, 4 si; and one st. The st is plumose, like the others. The Ri has 1,1,5 seta. The se of B2 is quite small and slender, longer on the third , Marine Copepoda 45k feet, as is the case in other species. In the males of Th. longispinosus and thompsoni, there are only three si on the Re3 of p 1, in addition to the st, according to Giesbrecht. 7°. Fig. 70. Th. bernardensis. Terminal portion of left antenna; only the primary bifurcation of the branched setz is shown. The material obtained by the Canadian Arctic Expedition constitutes an imperfect index to the wealth of elemental life in the northern waters of Canada. The Copepods, as a class, provide fish food for food fish. There is an inexhaust- ible supply of this fish food in the Arctic ocean, whence it filters down into the northern seas, where commercial fisheries are carried on. By tracing out the southern extension of arctic and sub-arctic forms, a great deal has been accomplished in giving precision to problems which await solution in the North Atlantic. Similar exploratory and experimental work is required for the North Pacific. In this way materials would be forthcoming which would enable the age-composition of the different colonies of organisms on the sea-floor to be made out. Equipped with such data we should be able to foretell the probable incidence of lean years in the fisheries. With this information at their disposal the capitalist corporations would be able to curb their tonnage so as to maintain an economic equilibrium between the market and the deep sea. This is what biological work can do for the deep sea and other fishery interests. Leaving out of consideration the salmon family and some other anadromous fishes, science cannot effectively replenish the stock of fishes in the sea, but it can claim to predict the periodicity of fluctuations when the necessary data have been accu- mulated after many years. No epidemics affect the plankton, but we know that higher animals are liable to various disorders and derangements whereby their numbers are reduced. The presence of an abundant food-supply does not unfailingly attract a multi- tude of feeders, and this fact, well-known to marine biologists and other natural- ists, but not so well known to those who have had no actual experience in the matter of the interdependence of organisms, indicates that while there is no limit to the supply of primary food-stuffs in the sea, there are limits, in some cases very narrow, in others very wide, but always very definite, to the valuable species which subsist directly or indirectly upon this food. Whilst investigating the distribution and periodicity of the food-organisms, the biologist is brought into contact with the feeders, and though his methods of extracting secrets from the sea may be slow, yet they are sure. Not sensa- 46K Canadian Arctic Expedition, 1913-18 tional discoveries, but dogged perseverance, such as that exhibited to good purpose by the members of the Canadian Arctic Expedition, should be en couraged with a free hand, for the glory of Canadian science and the protection of Canadian maritime industry. : Montreal, June 30, 1919. Report of the Canadian Arctic Expedition, 1913-1918. Volume I: General Introduction, Narrative, Etc. ee Northern Party, 1913-18. | : C, vay Bs Southern Party, 1913-16. By Rudolph Martin ‘Anderson.. (In preparation). - Pa ’ Volume Ij: Mammals and Birds. — Part A: Mammals, By Rudolph. Martin Anderson. (In préparation). : Part B: Birds. By R. M, Anderson and P. A? Taverner. ns preparation). Gt as Volume II: Insects. | Tatrodnation. ‘By C. Gordon Hewitt. (In press), Part A: Collembola. By Justus W. Folsom. (Issued). : ‘Part B: Neuropteroid Insects. By Nathan Banks. (Issued). i a : Part C: Diptera. By’ Chas, W. Alexander, Harrison G. Dyar, and ih Hy Malloobe (Tasted). - ° Part D: Mallophaga and eae By A. W. Baker, G. F. Ferris, and 3 G.H:F . Nuttall. (Iseued). Part E: Coleoptera. By J. M. Swaine, H. C. Fall, C.W. Leng, and J. D . Sherman, Jr. - (Issued). art F: Hemiptera. By’E. P. Van Duzee. (Issued). art G: Hymenoptera and Plant Galls. By Alex. D. MacGillivray, ‘Charles T. Brues, P.W.L. Sladen, and E. Porter Felt. (Issued). mo aa Mites, and Myriapods. By J. H. Emerton, Nathan Banks, and Ralph V. Chamberlin. Teeu oe 5 2 oh, a Part I: Lepidoptera. By Arthur Gibson. (Issued). : ( Part J: Orthoptera.. By E.M. Walker. (In press). : Part K: General Observations on Insect Life in the Aretie. By Frits Johansen. (In preparation). J Volume IV: Botany. ; Part A: Frehwater Algae and Ereehmater iatoms. By Charles W. Lowe. (In preparation). Part B: Marine Algae. By F. Collins. (In preparation). ra Part C: Fungi. By Jobn Desiee (In Dre DaralOn).- cs ‘ ’ Part D: Lichens. By K.L. Merrill. (In preparation). | Part E: Mosses. a R.S. Williams. (In preas). | 4 Volume V: Botany. - Part A: Flowering Plants and Ferns By James M. Macoun and Theodore Holm. ee repro. Part B: General Bistes on Arctic Vegetation. By Frits Johansen. (In preparation). - Volume VI: Fishes, Tunicates, Etc. - / Part A: “rishioas* By F. Johansen. (In preparation). - Part B: Ascidians, etc. By A. G. Huntsman. (In preparation). ’ Velume VII: Crustacea. ‘Part A: Decapod Crustaceans. ‘By Mary J. Rathbun. (Issued). Part B: Schizopod Crustgogaat. By Waldo L; Schmitt, / Ussued). Part C: Cumacea. By.W.T . Calman. ‘dn press). Part D: Isopoda. By Miss P. Li: Boone. “(In press). ° pS Part E: Amphipoda. By Clarence R:.Shoemaker. (In oe Part F: Pycnogonida. Leon J.Cole. (In press). Part G: Euphyllopoda. By F. Johansen, (In preparation). Part’ H: Cladocera. By Chancey Juday. (In press). ‘ ss Part-I: Ostracoda. By R. W. Sharpe. (In preparaien). ; .Part J: Freshwater Copepoda. “By C. Dwight Marsh. (Issued). ’Part K: Marine Copepoda.. By A. Wiley: (Issued), Part L: Patasitic Copepoda. By Chas. B. Wilson. (In press). Part M: Cirripedia. By H..A. Pilsbry. (In preparation). : Volume VII: Mollusks, Echinoderms, iecteniseatees 2 Ete. Part A: Mollusks, Recent and Pleistocene. By Wm. H. Dall. _ (Issued). Part B: Cephalopoda and Pteropoda. By S.S. Berry and W. F. Clapp. » (In preparation). “Part C: Echinoderms. ,By Austin H. Clark. (Issued). - 7 Part D: Bryozoa. By R.-C. Osburn. (In preparation). a ! Part E: Rotatoria. By H. K. Harring. © (In preparation). Part F: Chaetognatha. By A.G. Huntsman. (In preparation). Part G: Actinozoa and Alcyonaria. By A. E. Verrill. (In. preparation). Part H: Medusae and Ctenophora. -By H. B. Bigelow; (In press)... Part I: Hydroids. By McLean Fraser. (In pa Tg Part J: Porifera, - Volume IX: Annelids, Parasitic ‘ince Protozoans, Etc. Part’A: Oligochaeta. By ‘Frank Smith and Paul S. Welch. (Issued). _ Part B: Polychaeta. By Ralph V. Chamberlin. . (Jn press). Part C: Hirudinea. By J.P. Moore. (In press). i Part D: Gephyrea: By Ralph V. Chamberlin. (Issued). el us Part E: Acanthocephala. By H.J. Van Cleave. (Issued).-. © * Part F: Nematoda. By N.A.Cobb. (In preparation). G: Trematoda. By A. R: Cooper. (In preparation). . 5 : Cesteda:. By A. R. Cooper. (In preparation). |. ‘ — 2 I: Turbellaria. By A. Hassell. (In preparation).. ° Gordiacea. t ; 4 : K: ‘Nemertini. - & rt L: Aenean ‘By J. W.Mavor. (In preparation). oF f Part M: Foraminifera. By J.A.Cushman. (Issued © Volume X: Plankton, re Tides, Hite. Part A: Plankton. Marine Diatoms. | By. Albert Mann. (In preparation). Part B: Tidal Observations and aults. ‘By W. Bell Dawson. ni n press) Part C:-Hydrography. (In preparation). ae n re ‘ \