ihy NK Sg WJ Ae / z \W/ Ml f / ‘ / \ OREN ~ A . X LS y; = " ee 9 74 ( x ' { 5 \ \ ¥ ~ / ~— ’ ———. nv oat in Nee (Separat-Abdruck aus dem »Zoologischen Anzeiger« No. 370. 1891.) INVERTEBRSY. ad BPOO0EY 7 FP ceaay tS — Crustacea * fT 7 * Wa rivar NEL }o= Preliminary List of Deep Water Crustacea in Green Lake, Wis., U. S. A. By C. Dwight Marsh, Ripon-College, Ripon. During the past season I made a large number of collections from the deep water of Green Lake, and while I wish to postpone a detai- led statement of the results until after further collections and study, I think a preliminary list of the Crustacea would be of interest to those making similar investigations. The collections were made between the months of August and November, inclusive, and in water between 17 and 49 meters in depth. The list is as follows: Diaptomus sicilis Forbes. Diaptomus minutus Lill}. Epischura lacustris Forbes. Limnocalanus macrurus Sars. Cyclops fluviatilis Herrick. Cyclops Thomas Forbes. Cyclops sp. Cypris sp. Daphnella brachyura Lievin. Daphnia kahlbergensis Schoedler. Bosmina sp. nov. Leptodora hyalina Lilly. Pontoporeia Hoyt Smith. Mysis relicta Loven. The new Bosmina will be described by Dr. O. E. Imhof. Diaptomus minutus Lillj. has not, to my knowledge, been found, hitherto, except in Newfoundland. Pontoporeia Hoyi Smith, has, I think, been reported only from Lake Superior and Lake Michigan, and the only American locality for Mysis relicta, Loven, has been these same lakes. In fact, a compari- son of this list with those published by Smith and Forbes of the fauna of the Great Lakes shows that the fauna of the deep water of Green Lake is almost identical with that of Lake Michigan. Ripon, Wis., U. 8. A., May 18, 1891. ce r ‘ . 5 ON THE DEEP WATER CRUSTACEA OF GREEN LAKE. . _ By C. DWIGHT MARSH. Read before the Wisconsin Academy of Sciences, Arts and. Letters, December 30th, 1891. .[Reprinted from volume VIII of the Transactions of the Academy.]. é he bal ie egy 4 193 3 eal es * iy y ON THE DEEP WATER CRUSTACEA OF GREEN LAKE. By C. DWIGHT MARSH. During the past two seasons I have become interested in the deep water fauna of Green Lake, and have made a large number of collections. While the results may not be particularly striking, I think they are of sufficient interest to warrant the presentation of a short paper on the subject. Because of its depth, Green Lake resembles, in the conditions controlling animal- life, the larger bodies of water, and might be ex- peeted to have a fauna somewhat different from that of the shallower lakes. My collections seem to justify this expectation. It is only within a few years that it has been deemed worth while to make any investigation of the fauna of deep water. Even after the ex- istence of a very rich pelagic fauna in the oceans was recognized, bodies — of fresh water were almost entirely neglected. Now, it is well known that our lakes have a pelagic fauna rich in individuals, if not in species, and a less abundant abyssal fauna. Most of the European lakes have been explored with more or less thoroughness. Especially noticeable is the extended work of Prof. Forel upon Lake Geneva and the smaller Swiss Lakes. In this copntry comparatively little has been done. Since the initia- tory work of Dr. Hoy in Lake Michigan, some twenty years ago, so far as I know, only two persons have published anything on this subject — Prof. S. I. Smith, and Prof. 8. A. Forbes. The bottom of Green Lake, in the deeper parts, is a fine blue clay, in which are great numbers of ostracod shells and some few shells of mol- luses. I submitted the molluses to Mr. C. T. Simpson of the United States National Museum, who tells me that there was nothing of especial interest among them. They were all littoral forms, and, in most ener probably washed in from shallower water. There were also several species of hydrachna, worms, and infusoria, which I have not worked out. The crustacean fauna is extremely abundant, although the number of species is small. ee * aI? r= MOR San ae 212 Wisconsin Academy of Sciences, Arts and Letters. The following species were noted: Diaptomus sicilis Forbes. # minutus Lill). Epischura lacustris Forbes. Limnocalanus macrurus Sars. Cyclops fluviatilis Herrick f serrulatus Fischer. Canthocamptus sp. Cypris sp. Daphnella brachyura Baird. Ceriodaphnia reticulata Jurine. Daphnia kalbergensis Schoedler. Bosmina sp. Alona glacialis Birge. Leptodora hyalina Lill). Pontoporeia Hoyt Smith. Mysis relicta Loven. There were, besides, several forms of cyclops, which seem to differ from any described American species. AsI am now engaged in a study of this genus, I will leave their description for a later publication. None of the species of cyclops which I have found is peculiar to the deep water, as I have found the same forms in the littoral zone of the lake, and in smaller bodies of water in the vicinity. The pelagic fauna consists mainly of the following species: Diap- tomus minutus Lillj; Diaptomus sicilts Forbes; Epischura lacustris Forbes; Limnocalanus macrurus Sars; Daphnia kalbergensis Schoedler;, Leptodora hyalina Lillj. All of these, with the exception of limnocalanus macrurus, come to the surface at night. The species of cyclops are repre- sented very sparingly, and canthocamptus, daphnella, ceriodaphnia, and. alona are quite rare. Evening collections showed vast numbers of diaptomus minutus and epischura lacustris, and in some cases of lepto- dora hyalina. I found bosmina very abundant in November, but rather rare in the summer months. The abyssal crustacea are cypris, ponto- poreia Hoyt Smith, mysis relicta Loven, and perhaps some of the forms of cyclops. Especial interest, perhaps, attaches to three species of the preceding list. Diaptomus minutus Lillj. is found in great numbers, being much more abundant than diaptomus sicilis Forbes. My specimens corre- spond very closely to the description by Lilljeborg, as given in “ Revis- -ion des Calanides d’EKau Douce,” by Guerne and Richard, differing only in the following particulars. The joints of the right fifth foot of the male are shorter and stouter, and the terminal claw is longer and some- what more slender; the lateral spine on the last joint is blunt. The inner ramus of the left foot is more nearly elliptical. The animal aver- The Deep Water Crustacea of Green Lake. 213 ages somewhat smaller than the type. These differences are so minute that I consider them only varietal, although they are constant in the specimens I have examined. Diaptomus minutus has been found, hitherto, only in Greenland and Newfoundland, although it seems probable that it is widely distributed over the northern part of North America. Pontoporeia Hoyt Smith, has been found, hitherto, only in Lake Super- ior and Lake Michigan. A species almost identical with it, pontoporeia afjinis Kroyer, occurs in the abyssal fauna of the Scandinavian lakes. Mysis relicta Loven, was first found in the Scandinavian lakes. It is so closely allied to mysis oculata Kroyer,a marine form found off the coast of Labrador and Greenland, as to be considered only a variety of that species. It was found in Lake Michigan by Dr. Hoy, receiving the name of mysis diluvianus from Prof. Stimpson. Later,.Prof. S. I. Smith collected specimens in Lake Superior. Ihave not had an opportunity to compare my specimens with those from the Great Lakes, or with the original description of the Scandinavian form, but I have {little doubt that they are identical with them. When we compare the deep water crustacea of Green Lake with those of Lake Michigan and Lake Superior, as shown in the lists published by Prof. Smith and Prof. Forbes, we find a striking similarity. That this should be true of the pelagic fauna is not strange, for it is easy to explain the migration of such forms from one body of water to another _ through the agency of water fowl. . The presence of pontoporeia Hoyt, and mysis relicta however, is not so easily explained. They are abyssal forms,found only in deep water, and never coming to the surface. Their presence in the Scandinavian lakes is explained by supposing that the bodies of water, in which they are found, were formerly connected with the sea, and that, when the ac- cess of salt water was cut off, the change to fresh water was so gradual that the animals accustomed themselves to their new conditions of exis- tence. They belong to the “fauna relegata” or “relickten-fauna” of the Germans. This explanation does not seem to apply to Green Lake. The lake is of glacial origin, a dam of drift at the western end prevent- ‘ing its waters from flowing into lake Puckaway. The outlet of the lake is a small stream flowing through the village of Dartford, and emptying into the Fox River. So far asI know, there is no geological evidence whatever of any connection of Green Lake with either the Mississippi Basin or the Great Lakes, by which these deep water animals could have migrated to their present location. The problem is one for which I can at present offer no solution. fia aay Les Aa Y Syed a f Ne, nee rite i ve AN 2 4 pat ; ‘ A i r Mende 7 heed ae re ce ‘ tv ee ip é ie s « ‘a ct AY Fai 2 H veel ay “ NOTES on DEPTH AND TEMPERATURE OF GREEN “LAKE. : By C. DWIGHT MARSH. ~— "Read Herre dies Wiseohsin Academy of Sciences, Arts and Letters, December 30th, 1891. ah [Reprinted from volume ‘VIII of the Transactions of the Academy. ] NOTES ON DEPTH AND TEMPERATURE OF GREEN LAKE. By C. DWIGHT MARSH. Green Lake is situated in Green Lake county,and is something over seven miles in length, and rather less than two miles in its greatest breadth. It extends in a northeast and southwest direction, and is con- sidered by geologists, to be of glacial origin, its shores at the western extremity being formed of drift hills. The lake is of especial interest because of its depth, it being, I think, the deepest lake within the limits of the state. : While at various times soundings have been made by which the deep- est parts of the lake were located with a fair amount of accuracy, the only attempt at systematic soundings was made some years ago by Prof. C. A. Kenaston, when he was connected with Ripon college. Through the kindness of Mr. Henry Wolcott, of Ripon, I was enabled to get the results of Prof. Kenaston’s work, The soundings were made in winter through the ice and the distances between stations chained off. Four lines of soundings were made: from Bowen’s cottage to Oak- wood Hotel, from Sandstone Bluff to Oakwood, from Sandstone Bluff to Sherwood Forest, and from Sandstone Bluff to Sugar Loaf. The following tables give the results: From Bowen’s Point to Oakwood. Distance. Depth. 64rds, |e (A 63 feet. ISoh AAS 96 6 * 4ITY B4 « 972 «& WW hs % Q7 « SARE 8 ERE hare 90 « 304 « -% 20 « 30) « yu 61 « 368 TU Ft 66 « a Ne 53. gaa LL Aw ass Ae IEA OO 49 spay! Lee 41 626 * Pool Shore. pentane: ) Rene 6 Soa rds. 2 =—§ YN 52 fleet. \ ae at te. 89 « "3 ae ee 75 6 wok, 160 “ "tae 91 « iro i, 160 « ee ; 155“ Bet as 151 “ 27 Ser 88 315 « ete, oT « Shad SHA L 25 395 grit, 48 « ce 427“ LOH, ey ay 491 ve From Sandstone to Sugar Loaf. Distance. hee Depth. ee 48rds. “VAx4r 75 fect: | ae 96 « Ie 136 ae 14 OS ae 160 « DOB (Br 180 « | ait SU eee I hia 190 « ee 560 “ 4 oo 195 « | | 720) ) [leY¥o 180 «“ eee 752 « {220% 152“ ; SiG (Zr u 49 « g96 VESEY From Sandstone to Sherwood Forest. Depth. Distance. 40 rds. we 150 feet. | a“ tos 160 « me 100 « ewe 159 «| mat. 196 “ tay 140 « a, 256 « Yaa 132 «. 992. « mt Seca 73 “ sig¢ «6 Vw ree eee 348 « C1 Meee Shore. _ From these tables and the profiles derived from them, it will be s that the eastern part of the lake is comparatively shallow, and ft. there is a bar not far from the center where the depth is only tw feet. The greatest depth—195 feet—is reached between Sau '=éBluff and Sugar Loaf. SS or ea eee ae ee RD rs Tae Wye SCA OMe ee AS Bene | MDE roe Be ae G Depth and Temperature of Green Lake. 217 I have made no attempt at systematic soundings, but, in connection with dredging, have always taken the depth at the time of the haul, and my figures agree in all respects with those of Prof. Kenaston, except that they are uniformly somewhat less; this is easily explained by the fact - that the level of the lake has been lower than usual for the past two or three years. In the western part of the lake but few soundings have been made by any one. Capt. Pierce tells me that the greatest depth he has found is 172 feet. Itis popularly supposed that the deepest place is between Sugar Loaf and the south shore, as that is the last place to freeze. I have found there, however, only 189 feet. It will be noticed that the littoral zone, in most parts of the lake, is very narrow, considerable depths being reached quite near the shore. When dredging in deep water, I also took surface and bottom tem- peratures. This work was done in Aug., Sept., and Oct. 1890, and July, 1891. As, so far as I know, very little work of this kind has been done in our lakes, I have thought the results worth recording, although my observations were too few to form a basis for any general inferences. For bottom temperatures, I used a Miller-Casella deep sea thermom- eter, loaned by the United States Commissioner of Fish and Fisheries, and for surface temperatures a common chemical thermometer. As the thermometers were not tested, the results may not be absolutely accur- ate. The deep sea thermometer was attached about two meters from the sounding lead, giving the “ bottom temperature.”- _ The following tables give the temperatures arranged by depths: Avueust, 1890. Depth. Surface tem. | Bottom tem. 17 meters. 75a OF 118 Jol 3 ote ON 94.5 D5. Eek oe 26. 7.45 33. 24, 7.2 36. 25.5 ft 40.5 26. if. 40.85 Day. vf 415 2A. Te 49. 94.5 i¢ 49,2. 24. ip 43. 24 he ELE LS anid Wie 2 age Se 6.6 46.75 24 6.6 48.45 22 6.6 be RW O79 Nene area Ue Ne ac bea Nagas ERD Leh Tage ee LA. RY A Oe IR: Yee Ce ata A 218 Wisconsin Academy of Sciences, Arts and Letters. JULY, 1891. Depth. Air tem. Surface tem. | Bottom tem. po SiON) OG ea 41.85 meters. 99° TG es ba Os eee 5 a 43.5 O36 23. 5.56 50. OD De ot 5.28 50.5 25. ies 5.28 Hb2, : 90.55 Do. 5.28 56. Ab | pale 5.28 yar 04-72 Vk 5.28 58. 26.3 5.28 We notice that in August, 1890, there was a uniform temperature of — 6.6° C. below a depth of 45 meters, and that up to 25 meters there was an elevation of temperature of only one degree. In July, 1891, the bot- tom temperature was 5.28° C. While we cannot compare temperatures taken in August, 1890, with those taken in July, 1891, I think we may fairly infer that the maximum bottom temperature in Green Lake is reached in August, and that it remains nearly the same during Septem- ber and October. The surface temperature is nearly the same in all the deeper parts of the lake. Swimmers, in crossing the lake, claim that they pass through “streaks” of different temperatures, but the ther- mometer determinations show a practical uniformity of surface tem- perature. In comparing these temperatures with those obtained by Prof. and Mrs. Peckham in Pine Lake (Trans. Wis. Acad. V, 273), I notice that although the surface temperatures in Pine Lake, in both July and August, are higher than in Green Lake, the temperature of the deep water. is nearly the same. For instance, in August, 1879, at a depth of 18.28 meters, the bottom temperature was 7.23° C., while the surface temperature at the same time was 24.44° C., and in July, at a depth of 24.38 meters, the bottom temperature was 5.56° C., and the surface tem- perature 26.12° C. Thus, at 24.38 meters, was reached very nearly the minimum temperature which I found in Green Lake at 50 meters and below. Trans. Wis. Acad. i Vol. VI, Pl. VI. CS nee ee ee SE) do 4@ 40 fo 6 be ive Ihe (90 Ace we We tie 28 Je Fro Ive Vie Ie HO Yio Kye Veo “We Kee Me the tip Phe bp bee te Mis. bie Tew Bou Cocre ad Qorkwoor | es! Pret A - awe: ia a a | S oaeeee a @ © 60 bo fm fe we 40 [fo dy dee ty dee tty Tp Dee iy Ve dio MO he we Wo We fe fe Me Tie fm bw dw Dowd itows : Dortiwood. - e ye A be we ‘\ Ric aot h Bie Vs t i et . f Map and Pvosiles of Green Lake according to K enastons Soundings I Sugarloas to Sandstone T Oakwood toBowms I Oakwood to Saucdstone TW Skkerwood to Sandstone ea & OS as sar fe be 1 ino tue lip fv lang he Sve ake Ate dey eur feo Wh Seale 25 Svopless SsCorizontal Vom = BOvLCAs “Verticar Vor = $0 Le eisitiiae — CC ee oe die Sm Sic tua Vin 26e WS Me te hee tM ? VPS ae Lae, We ve Be, PN ny ats aa) , se ; = ; : | bes WO? 7 nek, 22, 204 LEA, (873. pp. 3 - 4 NOTES ON THE COPEPODA OF WISCONSIN, BY C. DWIGHT MARSH, RIPON, WISCONSIN. In the waters of Wisconsin and in the adjacent lakes are found the following twenty-one species of free-swimming copepods: Diaptomus sanguineus, Forbes; D. leytopus, Forbes; D. zalli- dus, Herrick; D. sicilis, Forbes; D. ashlandi sp. nov; D. mi- nutus, Lillj.; D. oregonensis, Lillj.; Epischura lacustris, Forbes; Limnocalanus macrurus, Sars; Cyclops americanus, sp. nov.; C. brevispinosus, Herrick; C. pulchellus. Koch; C. navus, Her- rick; C. zarcus, Herrick; C. leucarti, Sars; C. signatus, Koch; C. modestus, Herrick; C. fluviatilis, Herrick: C. serrulatus, Fischer; C. phaleratus, Koch; C fimbriatus. Fischer. Although two of these, D, ashlandi and C. americanus, are new species, it is not probable that they are peculiar to the Wis- consin fauna. The copepods of America have thus far received very little attention, the only important publications on the sub- ject being by three men, Professor Cragin, Professor Herrick and Professor Forbes. If more were known of our copepods it is probable that it would be found that there are few local differ- ences in the faunz of our northern States. The copepods are readily transported from one body of water to another and, without change of structure, seem to endure great changes in their environment. In fact, half of our species of cyclops are not only widely distributed in America, but are identical with those of Europe. Those that may be considered distinctly Amer- ican are closely allied to well-known European forms. C. leucarti is found in nearly all parts of the world where col- lections have been made and, so far as can be inferred from the published descriptions, varies but little, even in the minute de- tails of its structure. C. americanus closely resembles C.. viridis, and is probably the species which -has by other American authors been identified with viridis. Although there seems to be good reason for sepa- rating it from the European species, the similarity of the two forms is so great that it is only by a close examination that the structural differences become apparent. It is very possible that C. brevispinosus should be considered a pelagic variety of C. americanus, thus reducing. by one the number of species peculiar to America. There is some reason, too, for supposing that C. navus is not specifically distinct from C. pulchellus. _ C. pulchellus is the common pelagic form of the Great Lakes. Although found in smaller lakes, it is more commonly replaced by C. brevispinosus, which is a species of wide distribution. C. navus is found only in stagnant pools. The most common of all our species is C. serrulatus. Rarelv is a collection without this form, which seems to adapt itself easily to very different surroundings. It has, however, wide 4 SCis limits of variation, and it is, perhaps, due to this fact that it is so universally distributed. The littoral and pelagic forms are so different that they have been considered specifically distinct. C. modestus is a rare form. Thus far it has been found in only a single locality in Wisconsin. None of the American species of Diaptomus is identical with those of Europe, although in some cases the relationship is very close. D. sicilis isthe common pelagic form of the Great Lakes, but occurs also in smaller bodies of water. D. ashlandi has been found only in the Great Lakes. The most common species in the smaller lakes is D. oregon- ensis. This was described by Lilljeborg from specimens col- ected in Oregon, and probably is common through our northern States. D. minutus is common in Newfoundland, Greenland and Iceland. It occurs in some of the small lakes in northern Wisconsin and in Green Lake. It is likely that it occurs quite generally through the northern part of North America, and pos- sibly central Wisconsin is near its southern limit. Especial interest attaches to the fauna of Green Lake. This is about seven miles long, with a maximum depth of nearly two hundred feet. While the pelagic fauna of the Great Lakes is quite distinct from that of the smaller lakes, we find in Green Lake both sets of faunz. D. sicilis and Limnocalanus macrurus I have not found outside the Great Lakes except in Green Lake. But besides these species the pelagic fauna of Green Lake in- cludes C. brevispinosus and C. fluviatilis, which are the charac- teristic species of the smaller lakes. A more detailed account of the Wisconsin copepoda will soon appear in the Transactions of the Wisconsin Academy. Wisconsin my ¥ ay . er x es 2 : S = ron? riers ee jh 5 : e . te Sine Les ; 2 ae sd from Volume IX of the Transactions of the Academy.] _ eee - : . = 2 : } 4 y ON THE CYCLOPIDAH AND CALANIDA OF CENTRAL WISCONSIN. By C. Dwiaut MarsH. The material on which this paper is based has been largely collected from the immediate vicinity of Ripon. The fauna of Green Lake I have been enabled to study with considerable thoroughness; I have not only made a large number of collec- tions, but they have been made at all seasons from early spring ‘to December, and the work has extended over several years. From some ponds in the neighborhood of Ripon, I have made similar repeated collections. From Lake Puckaway, Lake Winnebago, and the smaller lakes in Fond du Lac and Green Lake counties, my collections were for the most part made in - the months of July and August. Through the kindness of Prof. E. A. Birge, I have also had material collected by him from lakes in the northern part of the state, and by Miss H. Merrill from the Great Lakes. This is not presented as a final report, for I still feel very doubtful in regard to the relationships of some species. But to properly define these relationships seems likely to involve a long period of study, and possibly it cannot be done satisfac- torily until more is known of the embryonic and larval stages. Inasmuch as so little has been published in regard to Ameri- can copepoda, I may be justified in publishing this paper, although I am well aware of its imperfections. While faunistic studies of fresh-water crustacea have been quite thoroughly prosecuted in Europe, and to some extent in Asia and Africa, only a few localities in the United States have been studied with any degree of thoroughness. The only considerable publications on copepoda have been made by Prof. Forbes, Prof. Cragin and Prof. Herrick. Prof. Forbes, who has made very important additions to our knowledge of BA. eh. PL Maar ¥ . A ty. rl A Pas \ AF at tas S aw z AOR ee a ; hit S pe o f- ED hs cate Ge t \ ‘ “ r fie ey 8 on 190 Marsh— Cyclopide and Calanidee of Wisconsin. Deena entomostraca, made his collections in Illinois, south- ern Wisconsin, the Great Lakes, and Montana and Wyoming. Prof Cragin collected in eastern Massachusetts. Prof. Her- rick has collected very widely through the Mississippi valley | and the southern states. His reports on the Minnesota crus- tacea (22, 29, 26) covered a region with a fauna nearly iden- tical with that of Wisconsin. His work of exploration must have been done very thoroughly, for my work in Wisconsin ~ gives me little to add in the way of new species. Because of incomplete descriptions or a lack of figures, it is, in some cases, however, difficult to identify his species. In Wisconsin the cladoceran fauna is better known than in any other part of the United States through the well-known © work of Prof. Birge, but the copepoda have been almost en- tirely neglected. | While the number of copepods in a collection from any locality is frequently very large, the number of species is generally small. In pools which are swarming with individ- uals, frequently there are not more than two or three species. In pelagic collections there are seldom more than four to six species. Of diaptomus there is ordinarily only one species in a locality, although two or three species are sometimes found together in pelagic collections. Some species ot copepods may be considered strictly pelagic, and some as strictly littoral, while others are found only in stagnant pools. But many species readily adapt themselves to all these conditions, and with little or no change of structure seem to thrive equally well wherever they may be. The following may be considered a fairly accurate division of the species according to their habitat: Distribution of the Species. RSs ES | Pelagic.| Litto- | oe ral. | Pools. MEM MEOTUIES SOTUGUIUCH SA. oi 2! aos ch ys o Fie Sa ht Pee aie kop) OE A REPOS ae he Pil ta Ge aha Cai soko RE Se x - pallidus ... x cf SO RIS ACCES cet AS NON fhe k Wise Ges x ct CSAOREE 05. os x ne LT AEIGE US PE Gee eee Seki oath x Ee ety eee aoe ~ OT EU OTIC SIS cy Ppt. Ons ae xe as Wee eure As AG seo MEE SCMAR CACUSLTAS Vic cL ed Le ah Timnocalanus macrurus.... x sees Cyclops americanus.... .. » WA eae te sol x Et CCELSIIILOSUS Ha oe cae kee ch een el. 53 ig at ee a x PERM ERO CI HONS 2 A Oa) Nese ie WY 210)» Wore BES AA re & ca lfhnger elds ay PUPCUS 06 i ie ee ee eee fe epee eee x PRE CCUCK ONT os os 8 - Bc 3 = SUGHOCUS 0. 0 oe x x x TR IMD CSO MRA sue nice Yolalb w ail ecrer ss ayecedl «ete ae % : BML OTOUD TONES cio So ag nc whe oe ss eames Jue raid JOS ateeee DISET RM GUS oa cho Site! ha oss aaah heh so x x Ua TA” a, Se ee ea Oe boomers (Oe oe KML OP MMCOLOE Ot ai LAs AON x CP IIMCOTUOCUS O06. Scie as tye es 58 x None of our species is peculiar to this immediate region, and it is probable that they are widely distriputed over the north- ern part of the United States and the southern part of British America. Indeed, the copepod fauna of North America resem- bles very closely that of Europe and northern Asia. This fact has already been remarked by Prof. Birge in regard to the cladocera, and it seems no less true of the copepoda. Many of our species are identical with those of Europe, even in the minutest details, as in the case of Cyclops leuckarti Sars. In other cases the structural differences are slight, and it is very probable that we should consider them of only varietal value, were we acquainted with the limits of species variation. That the species should be identical, or nearly so, over such a wide extent of territory is not at all strange when we remember how easily the living animals and their eggs may be trans- ported by water-fowl. Most of the forms, too, seem to readily AOE ie Marsh—Cyclopidee and Calanide of Wisconsin. ‘ adapt themselves to change of environment with little percep- tible change of structure. Thus Cyclops pulchellus Koch, is a common pelagic form of the larger lakes, and seems well adapted to its environment, but I have found it in Rush Lake, a reed- covered, shallow body of water, in which we would hardly expect to find any distinctive pelagic fauna. It is to be noticed that the American species of Diaptomus are distinct from those of Europe, and that they are, in some cases, quite limited in their distribution. The pelagic species are generally colorless, and the body and appendages are more elongated than in the littoral forms. — When a species occurs both in shallow and in deep water, the same difference is noted, the pelagic forms in some cases form- ing well marked varieties. The species of shallow water and stagnant pools are fre- quently highly colored, but the color is generally of little value in distinguishing species. Quite generally all the cope- poda and cladocera of a pool have the same prevailing color, while the same species under other conditions of environment may be entirely colorless. This was noticed by Herrick in 1883 (25 p. 385.) Certain species, however, seem to have a coloration peculiarly their own,—like the purple tips of the antenne in Diaptomus leptopus. The specimens of Cyclops modestus which I have found, have possessed a distinct purple tinge, very different from the colors of the species with which they were associated. In the synonomy of species I have followed the European authors. It seems to me next to an impossibility to identify the species of Koch and Baird, for their descriptions are of no ‘value whatever. All that is left for one to do is to accept them as defined by later authors. It has not been my aim to add to the already sufficiently numerous descriptions of “new species,” but rather to make more clear the descriptions already given, to indicate the proper synonymy, and to reduce the number of specific names rather than to increase them. In doing this, I know I have — laid myself open to criticism, for it is, perhaps, presuming too much to revise another author’s descriptions. My only excuse Distribution of the Species. 193 is my reluctance to add to the cumbersome nomenclature of the genera under discussion. For example, I have no doubt of the identity of a Wisconsin species with Cyclops brevispinosus Her- rick, but Herrick’s description is not sufficient for a satisfac- tory identification. Therefore, rather than to add a new species name, I have ventured to describe this species more completely. Inasmuch as printed descriptions, even when accurate, are frequently misleading, and as a list of species is only valuable when one is certain of the accuracy of the identification, I have, in most cases, drawn figures of the essential anatomical char- acteristics of the species treated of, and trust that I shall have made clear at least what species I have described, and have rendered it possible, if I have made mistakes, for others to ‘detect those mistakes. | Ig ES S\2 SiS hie Ed ie) . = oO SIFISlaAlSl-..lala S| 212 B/S/E/Ols|o eS] o) eg |e ins] le ehh Calg (eb Mle o}O S 3B iY Hol IS \FA = ees el alo it a ao S O53 (od) (ee as ata H|D/VD1ie rat) OCIS i4rol Hy |2i/Si¥ lx lolg Slee pen 1 POS 1 Obes les ig les ee eal (sae oiaadl onl (el CC Diapiomus sanguineus...........|.. Sar %% ot WEPUOM US Are PIE Oe TP ae feet ier: x ne COLETTI Se aie ae ete aa trl gn Ree > SAREE eta Irie be aL SUIS ei. Se Re LX a aa Mote ee SLID 88. alg hy eh el osss| ass ats ee, ae WEVA VR 2A ho es as x ache AS REN iets |e ae hans a OFEDONENSIS 202 ee ie ae Gite SS © 2h 24 Pe PO PUSCAUT@ NUEUSITIS a eX |: Klos Limnocalanus macrurus.. 0.6.2... me ane, Pos Cyclops americanus.... aah

A. 21 Po-7) EA l W o ie oa -tlb V BS TOD IDE cs Rian ol ay ea shore a 013! ot Beatle (8! be oat LP ber EN MMC WCNPUG Fb ela eas Lope sb SS b AN $s LOE CHES Pare Gin, «ot Maa 5) oe ye BY hea tide x UCN ERCISAT HU! a wards -< agian « er Vrs be a (ead el aed eae te ou SAQIOROUS 75a oto aN alate ie, xo | OER 2 > Sale. bo. A ead SEAT) UE Aiba ie woo iy a2 SP cal oa : ic” fluviatilis. Wt4wrd ... -. |X| x]..|.. met oh eee SE SCH ATU eats. a Pe el Ke Ke | we | ew x px Pees MIEMD EEO MS ot Sa a 0's” SEP mabe st aac i: chs * a DICOIO C cal tea Wet ae odin tise aa x . ! SER ATUIDOTIUES. s sh5 ic en. are « y ee x 194 Marsh—Cyclopide and Calanide of Wisconsin. | The foregoing table will give an idea of the distribution of the species in some of the bodies of water which I have exam- ined. Green Lake is about seven miles long and has a max- imum depth of a little less than two hundred feet. The other lakes—the Great Lakes excepted—are shallow. Lake Winne- bago, although a large body of water, is said to be nowhere more than twenty-five or thirty feet in depth. Rush Lake is pretty largely covered with a growth of rushes and wild rice, and is being gradually filled up. Lake Puckaway is an expan- sion of Fox river, is to a considerable extent covered with wild rice and rushes, and is very shallow. FAMILY CALANIDA. | GENUS DIAPTOMUS Westwood. KEY TO SPECIES OF DIAPTOMUS FROM CHARACTERISTICS OF MALE. Antepenultimate joint of antenna without appendage, Fifth feet nearly equal in length, oregonensis. Left fifth foot shorter than right, pallidus. Antepenultimate joint of antenna with hyaline lamella, /eptopus. Antepenultimate joint of antenna with appendage, ‘ Appendage short and blunt, : sanguineus. Appendage as long or longer than penultimate joint, Terminal hook of right fifth foot broad, lateral spine minute, minutus. Terminal hook falciform, Lateral spine nearer outer extremity of joint, sictilis. Lateral spine stout, near base of joint, ashlandi. ee: . ara Spheaige* ae . 2 Diaptomus. 195 DIAPTOMUS SANGUINEUS Forbes. Plate III. Figs. 1-3. 1876. D. sanguineus Forbes (17) pp. 15, 16 and 23, figs. 24, and 28-30. 1882. D. sanguineus Forbes (22) p. 647, pi. VIII, figs. 1-7, and Ls: 1834. D. sangwineus Herrick (26) p. 138, pl. Q, fig. 12. minnetonka Herrick (26) p. 138, pl. Q, figs. 8-10. sanguineus DeGuerne and Richard (32) p. 20, pl. IV, fig. 24. 6 ¢ Se ot a ni ca ~ This species, which is found in pools in the spring months, ‘is readily recognized by the characters of the male antenne and fifth feet. My specimens differ in minute particulars from the figures given by Forbes; the lateral spine on the terminal joint of the outer ramus of the right fifth foot in the male is nearer the distal end of the joint, while Forbes’s figure makes its position nearly median; the blunt spine on the inner angle of the second joint of this foot is a little longer than the spine at the outer angle, instead of shorter, as in his figure. D. minnetonka Herrick is probably a variety of D. san- guineus. DIAPTOMUS LEPTOPUS Forbes. Plate III. Figs. 4 and 5. 1882. D. leptopus Forbes (22) p. 646, pl. VIII, figs. 17-19. 1884. ‘‘ longicornis var. leptopus Herrick (26) p. 140. 1889. <‘‘ leptopus DeGuerne and Richard (32) pl. I, fig. 19, pk Tih ae. 9. Forbes, in his description, states that the antepenultimate segment of the right male antenna bears a small hook. I have failed to find a hook in my specimens; the segment is armed only with a very inconspicuous hyaline lamella. DeGuerne and Richard have also noted the absence of the hook. 4 196 Marsh—Cyclopide and Calanide of Wisconsin. It is quite common in the summer and fall months. As I have found it, it has been of a brownish red color, much like aD): sanguineus, with purple tipped antenne and caudal sete. D. kentuckyensis Chambers, is probably identical with Jepto- pus, although the imperfect figures make it impossible to decide with certainty. DIAPTOMUS PALLIDUS Herrick. Plate III. Figs. 6, 7 and 9. 1879. D. pallidus, Herrick (18a) p. 91, pl. II, a-d. 1884. > of s! (26) p. 142,-pl. .Q, fig. 17. OBO. 2 < 5 DeGuerne and Richard (32) p. 62, fig. 17. A small, slender species. Cephalothorax elongated oval, widest at about the middle; the last Pes eL! is armed with two minute lateral spines. The first abdominal segment of the female is as long as the remaining part of the abdomen, and is dilated laterally. The second abdominal segment is shorter than the third. The furcal joints are about twice as long as broad. The antenne reach beyond the furca. The right antenna of the male is swollen anterior to the geniculating joint; it bears no appendage on the antepenultimate joint. The outer ramus of the fifth foot of the female is two-jointed ; the third joint is represented by two blunt spines. The inner ramus is one-jointed, equaling in length the first joint of the outer ramus; it is armed with a short spine at tip, and two larger ones on inner margin of tip; the inner surface of the tip is covered with short hairs. The fifth feet of the male are slender, with the basal joints. nearly equal in length. The first joint of the outer ramus of the right foot is a little shorter than the basal joint. The second joint is nearly twice as long as the first; on its inner — margin at about a third of its length is a short spine-like pro- jection; the lateral spine is slender, situated near the outer end of the joint. The terminal hook is falciform, but-not with SO ella dl alls Diaptomus, : aos aft a regular curvature, and is about once and a half the length of the second joint. The inner ramus is slender, one-jointed, as long as the first joint of the outer ramus. The left foot extends to nearly one half the length of the second joint of the outer ramus of the right. The first joint of the outer ramus is about as long as the first joint of the outer ramus of the right foot. The second joint terminates in two projections,—a blunt finger-like process on the exterior side, with a pad armed with minute spines on its inner surface, and a slender falciform process from the inner margin, which curves over and nearly meets the process on the outer margin. There is also a small blunt projection on the inner margin of the joint. The inner ramus is slender, one-jointed, and equals in length the first joint of the outer ramus. Length of the male, .875 mm. ; of the female, 1.01 mm. Locality, Heart Lake, near Marquette. Herrick’s descriptions of D. pallidus are not sufficient to identify the species, and his figures in the report of 1878 do not help the matter. In the final report on the Minnesota Crustacea, there is but one figure of pallidus—that of the left fifth foot of the male—and it is mainly from this figure that I have considered D. pallidus identical «swith my specimens. I have not found it quite as large as stated by Herrick, but in other respects it corresponds quite well with his descriptions, and it does not seem best to introduce a new name. I have found D. pallidus in only one locality—Heart Lake, a small shallow lake south of Marquette. DIAPTOMUS SICILIS Forbes. Plate III. Figs. 8 and 10. 1882. WD. sicilis Forbes (22) p. 645, pl. VIII, figs. 9 and 20. 1884. « « Herrick (26) p. 142, pl. Q, fig. 18. 1889. «§< ‘¢ DeGuerne and Richard (30) p. 23, figs. 13 and 14, pl. II, fig 13. 1891. WD. sicilis Forbes (35) p. 702, pl. 1, fig 6. 198 Marsh—Cyclopide and Calunidee of Wisconsin. This species, which is abundant in the Great Lakes, I found as a common pelagic species in Green Lake in the summers of 1890 and 1891. In a large number of collections made in 1892, however, I did not find a single individual. This seems par- ticularly strange, as the collections in 1892 were made at about the same seasons as in the preceding years. The Green Lake specimens differ slightly from Forbes’s type. They are somewhat smaller, the males averaging .9 mm., and the females 1.08mm. The inner rami of the male fifth feet are | not evidently two-jointed. ; os ~~ re ee ee DIAPTOMUS ASHLANDI Sp. nov. Plate 410i.) Wies:<11= 13: A small pelagic species closely resembling D. sicilis Forbes. | j In form it is slender, hardly to be distinguished from D. sicilis and D. minutus. The first joint of the abdomen in the female is longer than the remaining part of the abdomen, is dilated at the sides, and bears two minute lateral spines. The second and third joints are so closely united that the abdomen appears two-jointed. The furcal joints are about twice as long as broad. The antenne reach just beyond the furca. The right antenna ot the male is much swollen anterior to the geniculating joint, and bears on the antepenultimate joint an appendage slightly exceeding in length the penultimate joint. ‘This appendage may be blunt pointed or slightly enlarged at the extremity. The fifth feet of the female are rather slender; the outer ramus is two-jointed. The third joint is represented by two short spines. The inner ramus is one-jointed, a little longer than the first joint of the outer ramus, armed at tip with two rather long spines. The fifth feet of the male are slender. The basal joint of the right foot is about twice as long as that of the left. The first joint of the outer ramus is a little wider than long. The second joint is wider at the inner than at the outer end; the Diaptomus. | 199 lateral spine is stout, curved, situated near the inner end. The terminal hook is slender and falciform. The inner ramus is slender, one-jointed, and about one-third ionger than the first joint of the outer ramus. . The left foot extends a little beyond the first joint of the outer ramus of the right. The second joint of the outer ramus has three blunt spines upon its apex and is armed with minute bristles within. The? inner ramus is slender, one-jointed, and reaches about half the length of the second joint of the outer ramus. Length of male, .89mm.,; female, .97 mm. Localities, Lake Superior and Lake Erie. D. ashlandi is smaller than D. sicilis, from which it is dis- tinguished by the form of the male fifth feet. The appendage of the antepenultimate joint of the right male antenna resem- bles the form in sicilis and minutus. The female is not so readily distinguished, although the fifth feet are more slender than in sicilis. I have specimens from only two localities. In pelagic col- lections made by Prof. Birge at Ashland it occurred with D. oregonensis and D. minutus. In a collection made by Miss Merrill on Lake Erie nearly all the Diaptomi belonged to this Species, D. sicilis being represented very sparingly. DraPpromus MinuTUS Lilljeborg. Plate IV. Figs. 1-8. 1889. Diaptomus minutus DeGuerne and Richard (Lilljeborg) (oe) p. 50, pl. I, figs. 5, 6 and 14, pl. III, fig. 25. 1891. Diaptomus minutus Marsh (38) p. 212. I reported D. minutus in 1891 from Green Lake. I have since found it in collections from the Great Lakes, the St. Clair river, and one Jake in northern Wisconsin. It was de- scribed by Lilljeborg from specimens obtained in Greenland and Newfoundland. It was later reported from Iceland (39). 200 Marsh—Cyclopide and Calanide of Wisconsin. It is probable, as stated by DeGuerne and Richard, that it is a common species through the northern part of North America. It is common in the pelagic collections from Green Lake, but I have found it nowhere else in central Wisconsin; it is possi- ble that this is near the southern limit of the species. The stout terminal claw of the outer ramus of the right fifth foot in the male, and the short, leaf-like inner rami of the fifth foot . of the female, make this species one easily recognized. DIAPTOMUS OREGONENSIS Lilljeborg. ‘Plate IV. Figs. 4 and 5. 1889. D. oregonensis DeGuerne and Richard (Lillj.) (32) p. 53, pl. 1 ie. 5) ple 1A, fers, This is the most common species of diaptomus, being found quite generally in the shallower lakes. It is easily distin- guished from the other species by the form of the male fifth foot. | The type specimens were obtained from Portland, Oregon, and according to the figures in DeGuerne and Richard’s ‘Re- vision” are somewhat more slender in all their parts than are my specimens. GENUS EPISCHURA Forbes. EPISCHURA LACUSTRIS Forbes. Plate 2V.02 hie. 6: 1882. EK. lacustris Forbes (22) pp. 541 and 648, pl. VIII, fos 15, 6, 21 G23. pk UX a tie 98: 1884. LH. lacustris Herrick (26) p. 131, pl. Q, fig. 13. 1889. <«§ v4 DeGuerne and Richard (32) p. 90, pl. IV, figs. 3, 9 and 10. 1891. £. lacustris Forbes (35) p. 704, pl. I, figs. 1-5, pl. II, igh ON gars arse Sacks ey ae, PS, Bre tet gic ie SNe cel a Sa ee 9 oe rns Cae Rl line BM AON BAe ia eters, We hes sy gi sage REE Te Tie cc geome Rte eho ae te a al oat = at tae eh b Bion, Limnocalanus. 201 I have found E. lacustris in only two localities beside the Great Lakes—in Green Lake and Lake Puckaway. Probably, however, it is abundant in other localities, as Forbes reports it from many lakes in Illinois, Michigan, and southern Wis rsin. The peculiar form of the male abdomen distinguishes nis in a striking manner from all other copepods. GENUS LIMNOCALANUS Sars. LIMNOCALANUS MACRURUS Sars. Plated Wi.) bie: 1863. LD. macrurus Sars (11) pp. 228-229. 1882. « as Forbes (22) p. 648. 1886. Centropages grimaldi DeGuerne (29) pp. 1-10. 1888. WL. macrurus Nordqvist (81) pp. 31-37, pl. I, figs. 9-11; pl. I figs. 1-5; pl. II figs. 1-4. 1889. L. macrurus DeGuerne and Richard (32) p. 77, pl. IV, figs. 5, 11 and 12. 1891. L. macrurus var. auctus Forbes (35) p. 706. LL. macrurus is abundant in Green Lake. It is a species of especial interest because of its wide distribution. It is found quite generally throughout northern Europe. Forbes has found it in Lake Michigan, Lake Superior and Lake Geneva. I have found it also in collections from Lake Huron, Lake St. Clair, and the St. Clair river. }" af ee , " ate Ae oa ae ee eer Ue ee Me ) , ‘ ied | nth, : fuk ey Pa a Re’ 4 LY ¥ . 7 202 Marsh—-Cyclopide and Calanide of. Wisconsin. 5 se Famity CYCLOPIDA. GENus CYCLOPS Mueller. KEY TO THE WISCONSIN SPECIES OF CYCLOPS, Antenne 17-jointed, fifth foot two-jointed, Second joint of fifth foot armed with seta and short spine, Terminal joint of outer branch of swimming feet armed externally with three spines, es Furca of moderate length, americanus. — he tic . Furca elongated, brevispinosus. Terminal joint of outer branch of swimming feet armed externally with two spines, parcus. Second joint of fifth foot with two terminal seta, Furcea short, NAVUS.. Furca elongated, pulchellus. Second joint of fifth foot, with one terminal and one lat- eral seta, leuckartt. Second joint of fifth foot, with three sete, signatus. Antenne 16-jointed, fifth foot 3-jointed, modestus. Antenne 12-jointed, fifth foot 1-jointed, Furea variable in length, armed externally with a row of small spines, serrulatus, — ‘Furea short, without armature of spines, fluviatilis. Antenne 11-jointed, swimming feet three-jointed, phaleratus. swimming feet two-jointed, bicolor. Antenne &-jointed, Jjimbriatus. CYCLOPS AMERICANUS Sp. nov. Plate IV. Figs. 8-10. 1882. C. ingens Herrick (23) p. 228, pl. V, figs. 1-8. 1883. <‘* viridis Cragin (24) p. 3, pl. IV, figs. 8-16. 1884.74. «+ ‘¢ Herrick (26) p. 145. Cyclops. , 203 Cephalothorax oval, the first segment being about half its total length. Antenne 17-jointed, about as long as first ceph- alothoracic segment. Abdomen rather slender, the last seg- ment armed on its posterior border with small spines. All the abdominal segments in immature individuals are strongly pectinated posteriorly. Furca about three times as long as its average breadth, the lateral spine situated well towards the end. The first and fourth terminal setz are short, slender and plumose, nearly equal in length. Of the internal sete, the outer is a little more than three-fourths the length of the inner. The armature of the terminal joints of the swimming feet is as follows: FIRST FOOT. Outer br. ex. 3 spines. Inner br. ex. 1 seta. ap. 2 sete. ap. 1 spine, 1 seta. im. 2. setae: - in. 3 sete. SECOND AND THIRD FEET. Outer br. ex. 3 spines. Inner br, ex. 1 seta. ap. 1 spine, 1 seta. ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete: | _ FOURTH FOOT. Outer br. ex. 3 spines. Inner br; ex: 1 seta. | ap. 1 spine, 1 seta. ap. 2 spines. in. 3 sete. in, 2 sete. Fifth foot two-jointed, basal joint very broad, armed with one seta. Terminal joint armed with a seta and a blunt spine. Length, 1.2 mm. | This takes the place in our fauna that is occupied by C. viridis Fischer, in Europe. In general form and appearance the two forms seem identical, and have been so considered by Herrick and Cragin. I have hesitated to propound a new Species name, but it seems necessary. ‘So far as Uljanin and Vosseler have figured viridis it corresponds to our species; but chem 204 . Marsh—Cyclopide and Calanide of Wisconsin. | neither gives figures of the swimming feet. From the original description by Fischer our species differs markedly. Accord- ing to his figure the antenne reach to the third cephalothoracic segment, while in americanus they hardly exceed the first. He makes the furca about equal in length to the last abdominal — segment; in americanus it equals or exceeds the last two seg- — ments. He gives a figure of “a foot,” not designating which, but it corresponds to no one of the four in our species. Sars says the terminal joint of the external ramus of the fourth foot has two external spines; americanus has three. Brady’s figure of the terminal joint of the outer branch of the fourth foot (18, pl. 20, fig. 7) corresponds to Sars’ state- — ment. He also figures the terminal joint of the inner branch (18, pl. 20, fig. 8,) which shows a very different armature from that in americanus. Schmeil (41, p. 97, pl. VIII, figs. 12-14,) gives a more elab orate description of viridis. His formula for the spines of the swimming feet corresponds to the descriptions of the other European authors. Schmeil, however, does not consider the armature of the swimming feet as constant, and according to his view americanus should be a variety of viridis. In an exam- ination of a large number of specimens from widely separated localities I have found no variation in the number and arrange- ment of the spines and sete of americanus, and until such vari- ation is shown, there seems to be no alternative but to insti- tute a new species for the American form. , @. americanus is widely distributed. It occurs quite gener- ally in stagnant pools, aud is also found to some extent in lakes. CYCLOPS BREVISPINOSUS Herrick. Plate IV. Figs. 11 and 12, 1884. C. brevispinosus Herrick (26) p. 148, pl. S, figs. 7-11. Cephalothorax oval, the first segment reaching about half its ee / } Cyclops. 205 total length. Antenne 17-jointed, shorter than first cephalo- thoracic segment. Abdomen. slender, the last segment armed on its posterior border with a row of small spines. Furca dO SDR TBE Ie ena i r r} r) slender, longer than the last two abdominal segments, lateral Spine at two-thirds the distance from base to extremity. Of the terminal sete, the outer is a short blunt spine, the inner slender and somewhat longer; the outer median seta rather -more than two-thirds the length of the inner. . The armature of the terminal joints of the swimming feet is I as follows: FIRST FOOT. Outer br. ex. 3 spines. Inner br. ex. | seta. ap. 2 sete. ap. 1 spine, 1 seta. in. 2 sete. in. 3 sete. SECOND FOOT. Outer br. ex. 3 spines. Inner br. ex. 1 seta. Beis t ap. 1 spine, 1 seta. ap. 1 spine, 1 seta. in. 3 sete. | in. ‘3 sete. THIRD FOOT. Outer br. ex. 3 spines. Inner br. ex. 1 spine. ap. 1 spine, 1 seta. ap. 2 spines. in. 3 sete. in. 3 sete. FOURTH FOOT. Outer br. ex. 3 spines. Inner br. ex. 1 spine. ap. 1 spine, 1 seta. ap. 2 spines. e . . in. 3 sete. in, 2 setee. The fifth foot is two-jointed. The basal joint is very broad and is armed with one seta. The terminal joint is armed with one seta and a short spine. , Length about 1 mm. Herrick’s® description of C. brevispinosus is so imperfect that it is difficult to identify the species with certainty. The armature of the swimming feet is different from that in C. par- cus, although one might infer from his statement that it is the . same. The form and armature of the furca, however, is char- 16—A. & L. é =e - : c EE ae | RS See Wepre te ee ee 206 Marsh—Cyclopide and Calanide of Wischncin | acteristic, and his figure of the furca makes me so certain of — pe the identity of the form, that I have ventured to redescribe the — a species rather than to propose a new name. It is easily rec- — as ognized by its short, 17-jointed antenne, and the elongated : ; furca, with the outer terminal seta reduced to a short blunt spine. It is widely distributed in lakes and ponds, and is a pelagic species, though sometimes occurring in littoral collections. I have had some doubt as to whether this should be consid- ered a distinct species. In most of its structural features it closely resembles americanus, and I have suspected it to be a pelagic variety of that species. I have specimens of amer- icanus with elongated furca like brevispinosus, and I have spec- : = imens of brevispinosus in which the outer terminal seta of the furca is slender and plumose as in americanus. For the differ-- ences in the armature of the swimming feet, however, I have as — yet found no intermediate forms, and so must, for the present | at least, consider the two distinct. CycLops NAvuws Herrick. Plate IV. Figs. 13-15. ae 1882. C. navus Herrick (23) p. ‘229, pl. V, figs. 6-3, tor (roto d CRaaRS eee ae i (26) p. 152. Larger than C. pulchellus, the antenne being about as long as first two segments of cephalothorax, as in that species. Armature of swimming feet as in pulchellus. Fifth fvot armed as in pulchellus, but terminal joint more elongated, and = its sete more nearly equal in length, the inner being fully two-— thirds the length of the outer. The furca is short, with the lateral seta on the posterior third; of the terminal sete the — first and fourth are short, the outer median about three-fifths “ as long as the inner. It is generally reddish in color and occurs in pools. Her- rick considers navus as probably a variety of pulchellus, and I am inclined to agree with him. The principal difference between the two species is in the form of the furca, and the difference is just that which we would expect from the difference of environ- ment. It is just the difference which exists between the Cyclops. : 207 extreme forms of serrulatus. So far as I know, however, no one has reported forms intermediate between C. pulchellus and C. navus. In my collections, while I have seen many instances of considerable variation in C. pulchellus, particularly in the form and armature of the furca, I have found no forms which at all approach ©. navus. Until such intermediate forms are _ discovered, C. navus must be considered distinct. CYCLOPS PULCHEnEUE Koch. Plate IV. Figs. 18 and 19. 1838. ©. pulchellus Koch (3) H. 21, pL 2 1857. ‘* bicuspidatus Claus (8), p. 209, pl. XI, figs. 6 and 7. le (2 eae BS Se Ge as pe at Ole: ‘1863. <‘* pulchellus Sars (11), p. 246. 1870. ‘* bicuspidatus Heller (12), p. 71. aero.“ bicusprdatus Fric (13), p. 221, fig. 6: 1876. ‘* bicuspidatus Hoek (16), p. 17, pl. I, figs. 7-11. 1880. ‘* pulchellus Rehberg (19), p. 543. 1880. ‘* helgolandicus Rehberg (20), p. 64, pl. IV, fig. 5. mace, '* thomast Forbes (22), p. 649, pl. IX, figs: 10,° 1 and 16. 1883. ,, pectinatus Herrick (25), p. 499, pl. VII, figs. 25-28. 1883. ‘* thomasi Cragin (24), p. 3, pl. III, figs. 1-13. 1884. « thomast Herrick (26), p. 151, pl. U, figs. 4, 5, 7 and 8. 1885. <‘ pulchellus Daday (2%), p. 220. 1886. ‘* pulchellus Vosseler (28), p. 194, pl. V, figs. 19-28. 1891. ‘* thomasi Forbes (35), p. 707, pl. I, fig. 8. 1891. ‘* bicuspidatus Brady (86), p. 13, pl. 5, figs. 1-5. 1891. ‘* thomasi Brady (36), p. 14, pl. VI, figs. 1-4. 1891. ‘© bicuspidatus Schmeil (37), p. 27. 3 1891. ‘* bicuspidatus Richard (39), p. 229, pl. VI, fig. 6. 1892. <‘* bicuspidatus Schmeil (41), p. 75, pl. II, figs. 1-3. 1893. <‘* thomasi Forbes (42), p. 249, pl. XX XIX, figs. 9-12; fe SE fe! 43. Herrick considered C. thomasi a variety of C. pulchellus Koch. Brady also raises the question as to the specific distinction of the American form. I have gone over the literature of the sub- ject with considerable care, and I can see no good reason for 208 Marsh—Cyclopide and Calanidee of Wisconsin. — separating our American form from C. pulchellus Koch, or bicus~ pidatus Claus. All the Huropean descriptions agree very closely mediately connected with large sheets of water.” : Herrick says, “it is one of the most abundant forms in the larger lakes, and especially in streams.” | me irine | Pe O ; E 4 %. = . : i = - 3 % a ‘* & = 3% + ———_—— ~< -_—~. eq ate ~ a ™ a) wee > a ft ~ “uu ‘ Fa Oe i os eh = So. 2 aes ~—e aa ae ein ee, r , , = 4 Cyclops. i wares 215 CYCLOPS SERRULATUS Fischer. Plate VI, figs. 2-5. 1838. OC. agilis Koch (3), H 21, pl. III. 1851. “ serrulatus Fischer (6), p. 423, pl. X, figs. 22, 26-31. —i8a5. * rs Lilljeborg (6), p. 158, pl. XV, fig. 12. Jy Claus (7), p. 36, figs. 1-3. clip iaaiaaa x Sars (11), p. 45. peweeos.." * Claus (9), p. 101, pl. I, figs. 1 and 2; pl. PV, feed 2> ph XI! fier. “3. aS ‘ Lubbock (10), p. 197. Peto 5 Heller (12), p. 6. 1872." - Frie (13), p. 222, fig. 18. er Uljanin (15), p. 34, pl. VIII, figs. 1-8. So. ke aa a Brady (18), p. 109, pl. XXII, figs. 1-14. 1880. “ agtlis Rehberg (19), p. 545. 1882. ° serrulatus Herrick (23), p. 230. 1883. “ pectinifer Cragin (24), p. 6, pl. IV, figs. 1-7. 1884. “ serrulatus Herrick (26), p. 157, pl. O, figs. 17-19. 1885. “ agilis Daday (27), p. 240. 1886. “ agilis Vosseler (28), p. 190, pl. V, figs. 29-31. 1891. “ serrulatus Schmeil ($7), p. 29. | 1 fo! a ae Pat Jotddy (eb) pS, plo Nal, fig. ¥. ae ff Richard (39), p. 234, pl. VI, fig. 19. BS92) 5" ie Schmeil (41), p. 141, pl. V, figs. 6-12. C. serrulatus is found everywhere. It is the most common of all the species of Cyclops. In the larger bodies of water it is more common in littoral collections, but it occurs not infre- quently in pelagic collections. This species has a wide limit of variation, the extreme forms differing so much that one is at first inclined to rank them as separate species. At one extreme is the form common in ditches, pools, and littoral collections, which seems to correspond nearly to montanus Brady. It averages .85 mm in length; the furca is not quite as long as the last two abdominal segments, and the external terminal seta is transformed into a stout spine 216 three-fourths as long as the furca, projecting iteeally tram the _ body. At the other extreme is the pelagic form, C. elegans Her.” | rick. It averages 1.25 mm in length. The furca is once anda third as long as the last two abdominal segments, and the ex- - ternal terminal seta is short and weak. > : Sometimes the two forms occur together in pelagic collec- tions, but only once have I found the elegans form asa littoral species. The European form is, in its characteristics, interme- + diate between these extreme forms. ¥ Although the extreme varieties sometimes occur together, — they are almost always entirely distinct. In only two localities | ‘a have I found connecting forms. In Heart Lake I found an in- eo termediate form associated with the smaller variety, and in Lake Puckaway I found the typical form in connection pfs? both extremes. : CYCLOPS PHALERATUS Koch. Plate VI, figs. 6 and 7. 1841... U. phaleratus Koch (3), H 21, pl. 1X. . 1851. “ canthocarpoides Fischer (5), p. 246, pl. X, 1S 24, 32238. LBBB nye Lilljeborg (6), p. 208. plea. < ¢ : Claus (7), p. 37, pl, I, figs. 6-10. iD ee 3 “~- (9), p. 102, pl. IV, figs. I= 1863..." : Lubbock (10), p. 202. pees 1863. “ phaleratus Sars (11), p. 46. 1872. “ canthocarpoides Fric (13), p. 223, fig. 19. 1874. “ Jascivus Poggenpol (14), p. 72, pl. XV, eS 2224: pl. XVI, figs. 7 and 8. 1875. “ phaleratus Uljanin (15), p. 38, pl. IX, He 1-5. | NB Fetes i Brady (18), p. 116, pl. XXIII, figs. 7-13. 1882. “ adolescens Herrick (23), p. 231, pl. VI, figs. 16-20. — 1883. “ perarmatus Cragin (24), p. 7, pl. I, figs. 9-18. . 1884. “ phaleratus Herrick (26), p. 161, pl. R, ee. 6-10. 1885.7 > Daday (27), p. 252. li orol Saibarte Herrick (80), p. 14, pl. VII, fig 2, a—d. Tesi Ey ame . Schmeil (37), p. 36. Cyclops. 216 1891. ©. phaleratus, Brady (36), p. 25, pl. TX, fig. 2. Teas" e Richard (39), p. 238, pl. VI, fig. 12. peor. S % Schmeil (41), p. 170; pl. VIII, figs. 1-2. The European C. phaleratus has ten-jointed antenne. Our Specimens ordinarily have eleven joints, although sometimes, according to Herrick, occurring with ten. In other respects, my specimens agree with those figured by European authors even in minute details, and there seems no good reason for making a new species of our form. It occurs quite widely distributed in the smaller lakes, and in stagnant pools. CYCLOPS BICOLOR Sars. 1863. . bicolor Sars (11), p. 253. 1880. “ diaphanus Rehberg (19), p. 547. Poe. Rerrick (26), p..160; pl. Ky fig. 12. i385 a Daday (27), p. 246. HSOh. . Herrick (80), p. 16, pl. VII, figs. 3a-e. 1891. ‘“ bicolor Schmeil (87), p. 34. | 1891. ‘“ diaphanus Richard (39), p. 236, pl. VI, fig. 26. ©1892,“ bicotor Schmeil (41), p. 118, pl. VI, figs. 6-13. The antenne are 11-jointed, hardly as long as the first cephal-. othoracic segment. The abdomen is somewhat elongated, the last segment armed with spines posteriorly. The furca is nearly as long as the last two abdominal segments. The lateral spine is situated at about the posterior third. The first and fourth terminal setee are short, the inner considerably longer than the outer. The median sete are strongly plumose, and the longer is about as long as the abdomen. The rami of the swimming feet are two-jointed. The arma- ture of the terminal joints is as follows: FIRST FOOT. Outer br. ex. 3 spines. Inner br. ex. 1 seta. ap. 2 sete. ap. 1 seta, 1 large spine. in. 3 sete. in. 3 sete. pet ig BP Seah DG << oe - 2% ae ae ‘ 218 | Marsh —Cylopies Be C atanidl SECOND AND THIRD FEET. Se gs. 1a Outer br.’ ex, 3 spines. - Inner br. ex. 1 seta. pes ap. 1 spine, 1 seta. ap. 1 spine, 1 seta. A in. 4 setee. eps eas in. 4 sete. ~ FOURTH FEET. . Outer br. ex. 2 spines. Inner br. ex. 1 seta. : ap. 1 spine, 1 seta. ap. 2 spines. in, 4 sete. in. 3 sete. The last cephalothoracic segment is expanded laterally, and d = bears upon each side a long seta. The fifth feet are attached to Bi these expansions, are one-jointed, linear, and each bears at the : Be: _ tip a single seta. a Females average a little more than $ mm. in length. The | _ color in all the specimens I have seen has been purplish. My ~ Q -—s specimens agree very well with the descriptions of Sars and Schmeil, the only marked difference being in the length of the a caudal sete. More complete descriptions of the European form RE may show other differences, but so far as the descriptions go, they apply very well to our form. ; Be C. bicolor occurs in stagnant pools, and is somewhat rare. CYCLOPS FIMBRIATUS Fischer. Plate VI, figs. 8 and 9. - =e 1785. C. crassicornis Mueller (1), p. 113, pl. XVIII, figs. 15-17. ean - a 1853. “ fimbriatus Fischer (5), p. 94, pl. III, figs. 19-28 and 30. | 3 ; 1863. ‘“ crassicornis Sars (11), p. 47: 1870. “. gredieri Heller (12), p. 8, pl. 1, figs. 3 and 4. 1872. _ “ pauper Fric (13), p. 223, fig. 20. Mea 1875. “ crassicornis Uljanin (15), p. 39, pl. VIII, figs. yee ihe pl. Mity fies ¥. : 1878.“ : Brady (18), p. 118, pl. XXIII, figs. ae 1880. ‘ poppet Rehberg (19), p. 550, pl. VI, figs. 9-11. 1880. “ fimbriatus Rehberg (19), p. 548, pl. VI, figs. 7 and 8. 1882. “ crassicornis Herrick (23), p. 232, pl. IV, figs. 9-14. * be }¢- - 5 aes ~ Biblio graphy. : 219 ad 1884. C fimbriatus Herrick (26), p. 162, pl. R, fig. 11. ESBS, ss Daday (27), p. 262. 1885. “ margot Daday (2%), p. 264, pl. III, figs. 20-25. TBS6. =" Je Ones Vosseler (28), p. 192, pl. VI, figs. 4-8. 1e9t.- Schmeil (37), p. 35. _ 2 Brady (86), p. 25, pl. IX, fig. 1. |e . Richard (39), p. 238, pl. VII, figs. 13° A and 14. io 3 oe : Schmeil (41), p. 161, pl. VII, figs. 8-13: This, our only eight-jointed species, I] have found in only two localities. It corresponds quite exactly wlth the descriptions of the European authors. Brady, however, in fig. 4, pl. XXIII of _ his monograph, represents the terminal joint of the inner ramus of the second foot as armed with a spine on the inner margin. In my specimens this joint has a se¢a on the inner margin. But making allowance for possible inaccuracies in the figure, I see _ no reason for doubting the identity of the forms. Herrick states that the color is always reddish. I have found nearly colorless individuals, and I think that the color of this, as of other species, varies according to the environment. BIBLIOGRAPHY. The following list of papers is not a complete bibliography of the cyclopide and calanide, but includes only those works bearing upon the species treated of. Of these I would make Special mention of the “Revision of the Calanide” by DeGuerne and Richard, which is a model of what such a work should be, and in its exactness of statement and beautiful plates, stands out in pleasing contrast with the crude productions of many of the other authors. 1. 1785. Muvertier, O. F. Entomostraca seu insecta testacea quee in aquis Daniz et Norvegie reperit, descripsit et _iconibus illustravit. 2. 1820. JURINE, L. Histoire des Monocles qui se trouvent aux environs de Geneve. noe ep aaae Pe , mi yr Pel des a 4 ? n 10. 11. 12. PAS: 14. 15. 16. 17. apoden und Arachniden. Til Mus: Nat. Hist, No, 1; » ee | oe. > * ¥ cc " . vitere = Bee ani LS “ wt Pe ‘2 , on clot Pet, Oe a +: » oa rs ng BY es i= 1835- 1841. Kocu, C. L. Deutschlands Grostheen: M5 1850. Barrp, W. Natural History of the British ee ‘ mostraca. Ray Soc. Lond. ae 1851-1853. FiscHEer, S. LBeitrage zur Renita der in. Sa der Umgegend von St. Petersburg sich findenden Cyclopi- den. (und Fortsetzung.) Bull. Soc. Imp. Moscow. : 3 i 1853. . LintsEBoRG, W. De Crustaceis ex ordinibus tribus:. Bees 7. Cladocera, Ostracoda, et Copepoda in Scania occurrentibus. 1857. Cxaus, C. Das Genus cyclops u. s. einheimische Arten. Archiv. fur Naturgeschichte, XXIII, 1Bd.p.1-40. 1857. Cuaus, C. Weitere Mittheil. uber d. einh. Cyclop- oe iden. ibid. p. 205-211. , ae 1863. CuLaus, C. Die freilebenden Copepoden mit became a dere berucksichtigung der fauna Deutschlands, der Nord- i see u. des Mittelmeeres. Leipzig. . 1863. Lussocx, J. Notes on some new or Titles known species of fresh-water entomostraca. Trans. Linn. Soe. 4 Lond. XXIV. a 1863. Sars, G. O. Oversigt af de indenlanske Fersk- = vandscopepoder. Forhandlinger i Videnskabs.—Selska-— ? bet i Christiania. 1862. ; 1870. Hewuer, C. Untersuchungen uber die Crustaceen Tyrols. Berichte des medic. naturw. Vereins in Inns- bruck. 1 Jhrg. pp. 67-96. tSi2., 1 RIC, AL Die Krustenthiere Boehmens. Archiv. der naturwiss. Landesdurchforschg. von Boehmen. IIL Bd. IV Abth. 1874. Poaernpot, M. J. List of the Copepoda, Cladocera and Ostracoda of the Environs of Moscow. (In Russian.) 1875. Uusantn, W. N. Crustacea of Turkestan. Part tI. (In Russian. ) 5, Oe 1876. -Horns P,P aCy 7 De. W erjlevende Toctwater -Cope-. -poden der Nederlandsche Fauna. Tijdsch. d. Nederl. Dier- — ee kund. Vereenig III. % 1876. Forses, 8. A. List of Illinois Crustacea. Bulls) — ag a A i FT LS ————————————— ee eee hr ene ese - eee - a a a = ay AE Ta 24. 27. _ Bibliography. 221 1878. Brapy, G. S. Monograph of the free and semi- parasitic copepoda of the British Islands. 3 vols. Ray Soe. Lond. _ 1879. Herrick, C. L. Microscopic Entomostraca. Ann. Rep. of Regents of Univ. of Minn. for 1878. pp. 81-123. 1880. ReuserG, H. Beitrag zur Kenntniss der freile- benden Susswasser Copepoden. Abh. d. natur. Ver. zu Bremen. Bd. VI, pp. 533-554. 1880. ReruHBerRG, H. Weitere Bemerk. uber d. freileben- den Sussw. Cop. Abh. d. natur. Ver. zu Bremen. Bd. VII, Hft. I, pp. 61-67. 1881. CHamBers, V. T. Two new species of entomos- taca. Journ. Cinn. Soc. Nat. Hist. IV. 1882. Forpes, S. A. On some entomostraca of Lake Michigan and adjacent waters. Amer. Nat. Vol. XVI, pp. 537-542, 640-649. 1882. Herrick, C. L. Cyclopide of Minn. with notes on other copepods. 10th Ann. Rep. Geol. and Nat. Hist. Sur. Minn. 1883. Cragin, F. W. A contribution to the history of the fresh-water copepoda. Trans. Kans. Acad. Sci., Vol. MALTS , 1883. Herrick, C. L. Heterogenetic development in d- aptomus. Amer, Nat. Vol. XVII, pp. 381-389, 499-505. 1884. Herrick, C. L. A final report on the crustacea of Minn. included in the orders cladocera and copepoda. 12th Avn. Rep. Geol. and Nat. Hist. Sur. Minn. 1885. Dapay, JENo. Monographia EKucopepodorum libero- rum in Hungaria hucusque repertorum. A. M. tud. Akad- emia altal a Vitez-alapbol. 1886. VossELER, J. Die freilebenden Copepoden Wurt- tembergs und angrenzender Gegenden. Inaugural Disser. der hohen Naturwissenschaftlichen Fakultat der Univer. Tubingen. Jahreshefte des Vereins fur vaterl. Natur- kunde in Wuertt., 1886. 1886. DrGuERNE, J. Description du Centropages Grim- aldii, Copepode nouveau du golfe de Finlande. Bull. Soc. Zool. France XI. 17-A.& L. 222 30. on. 32. 33. o4, 35. 36. ot. 38. 39, 40. 41. Marsh—Cyclopidee and Calanide of Wisconsin. 1887, Herrick, C. L. Contribution to the fauna of the Gulf of Mexico and the South. Mem. of Denison Assoc. ae a Vol. I, No. 1. ‘Se 1888. Norpevist, O. Die Calaniden Finlands. Bidr. till.. Kanned. af Finlands Natur och Folk; heft 47. (Finsk. bs” Vet. Soc. Helsingfors.) Cr a a 1889. DrGuERNe eT Ricard. Revision des Calanides d’eau douce. Mem. de la Soc. Zool. de France. Vol. II. he 1889. DrGuERNE ET RicHarp. Sur la faune des eaux douce du Groenland. Bull. Soc. Entom. Fr. 25 mars, 1889. 1891. DrGuERNE ET RICHARD. Sur quelques entomos- traces d’eau douce de Madagascar. Bull. de la Soc. Zool. de Fr. T. XVI, p. 223.- . 6s 1891. Forsers, S. A. On some Lake Superior entomos- 4 traca. Rep. U. S. Com. Fish and Fisheries, 1887.) pp: 701-718. 1891. Brapy, G. 8S. Revision of British species of Fresh- water Cyclopide and Calanide. Nat. Hist. Trans. North- umb., Durham, and Newce. Vol. XI. ahaa 1891. ScumeEIL, Otro. SBeitrage zur Kenntniss der freile- beden Susswasser Copepoden Deutschlands mit besondere Berucksichtigung der Cyclopiden. Zeitschr. f. Naturw. Halle. 64 Bd. 1 and 2 Hft. : 1891. Marsy, C. D. On the deep-water crustacea of Green Lake: Trans. Wis. Acad. Vol. VIII: 1891. RicHarp, Juu. Recherches sur le systeme glandu- laire et sur le systeme nerveux des copepodes libres d’eau douce, suivie d’une revision des especes de ce groupe qui vivent en France. Ann. Se. Nat. Zool. T. 12. 1892, DeGurrne et Richarp. Sur Ja faune des eaux douce de |’Islande. Bull. Soc. Entom. Fr., 8. fevrier, 1892. 1892. ScumeErL, Orto. Deutschlands Freilebende Suss- wasser Copepoden. 1 Thiel: Cyclopide. Bib. Zool. Heft II. : 1893. Forses, S. A. aie ig ny at r i 4 MICHIGAN FISH COMMISSION—BULLETIN NO. 5. 5, Collections made by Dr. R. H. Ward in September, 1894, in Emmet. and Cheboygan Counties, along the “Inland Route.” Inasmuch as these collections were made for the most part, in the summer season, and more especial attention was paid to the larger bodies. of water, the results of the examination cannot be considered as giving us. a complete knowledge of the fauna of the State. A more careful examina- _ tion of the smaller lakes and of the stagnant pools would doubtless add — some species to the list. Yet the number of those species would be small, — and for the larger bodies of water the list as given in this paper is prob- ably very nearly complete. This becomes evident when one remembers how nearly identical are the — | faunee of the deeper waters of our lakes. To such an extent is this true that one can prophesy quite exactly what species will be found in a collec- tion from any of the lakes of this latitude. The collections from the deeper water will almost invariably give the following species:—Diaptomus- oregonensis, Cyclops brevispinosus, C. Leuckarti and C. fluviatilis. C. albidus and C. serrulatus may be present, but belong more properly tothe ~ littoral fauna. In the larger lakes, in addition to this list we may find Epischura lacustris. Diaptomus sicilis, D. Ashlandi, D, minutus, and Limnocalanus macrurus are not commonly found except in the Great Lakes and in the bodies of water in direct connection with them; in the Great. Lakes, too, C. pulchellus takes the place which C. brevispinosus holds in the smaller lakes. D, Reighardi is the only new species which I have found in the Michi- gan collections. As I have already remarked in a former paper (93 p. 192) the species of Diaptomus are, in some cases, quite limited in their distribu- tion, and apparently Diaptomus is much more susceptible to the influences. — of its environment than is Cyclops. Very little is known of the life his- tories of the species of Diaptomus, and it is possible that a more complete knowledge may lead to a reduction of the number of species. But, sofar — as I can see, all the forms described vary within comparatively narrow limits, and there is no evidence whatever to lead us to question the separa- tion of the forms. I have indicated, in the accompanying chart, the distribution of the vidual collections in Lake St. Clair and Lake Michigan as no particular significance is attached to such facts. , The sketch maps will show most of the localities where the collections. were made, It is interesting to note the greater richness of the copepod faune of our lakes as compared with those of the continent of Europe. Zacharias finds — seven species of copepods belonging to the Cyclopide and Calanide in the Pléner See. In Lake Michigan there are nine, and that includes no. littoral species; in the lakes on the Beaver Island there are eight, in Pine: Lake nine, in Round Lake eleven, in Intermediate Lake eleven, and in, Lake St. Clair sixteen. The large number in Lake St. Clair is probably — explained by the fact that, being very shallow, it has the species of the smaller bodies of water and of the stagnant pools, and in addition, because: of its connection with the Great Lakes, has also their limnetic species. \ b Ten) Roi ies aan SR Fic) Mah ake al aay Dt el ct | age pe EA a2 Saal Faia ge 5 ore es eee ee et Be ee a | eo a 4 [ecceee [ecenee[eeeee-[eeee cree eens ee Heels ( ee shit ean Stren ters | anaes ee aio firateall apse oe oaeeel ary el Se esha Ses sojoolq,, Kd +--+ + Sie2 cer gerra| «realest: oe (ego at a, 3 sae Se a a 4 ei eee ef snjeseyeqd ” 2 + -+ weep ty Ber See Se si a as pies: po fee re pee eee i : “e “i a =I aa woes snye[N1108 ” eta | ede | epee] le [eetfee fee freer fee] seep ee freee fee aes ire eae Sete es aes poe sITyerany ,, a eS es ees een (ec beeen eee eee eed eed peer a Ste mala at at cs ated Teas | ret eee) (akan ee sup! Se Ce hapa age a eae a eel aay Ma ae aoe 4 fecee cfenceee fone ene|eee eee foneeee] 222] qj ” jo) aia ee aes Bt | ct | tat se Ore a eke ewe oe ae leat oPeciee ar a ae alee sno; | th + ee | Si 6 aL 4. fe were |---e- ” 5 in ee eae Begs fle esl es tleet ae | soe), carla, | ete ee tome ed Seip rs ote alee ce I oe oll pectaee | amines aoe ee ea yaeyoue'T, = ee io Ra Peele Se 4 feceees[ereceeteree- | | ge | eee gol hace Pelee SE aks |e snoTed 4, S ag Fy Fa (i 4 poses fesse] ese ee=|-=eee- ac lPaeee a: Slaps rae ee Sale altace snyjeqoyud =, Beet ee | et | tg | ma nal nee | vom oae es ts ee ees eee a a sts 2 a sonics a SnSsOUIdsIAGIq—,, gq | A ee eoee eee eRe = Coa area ee sow sd0p969 & soos ame le ae ete ate eal nae ate sleet Peete Pele tie | cme ee ae alas ep ee : Gass ob ee snINIOBUI SUUB[BOOUMIT] ee rt ee ok) tpi Sede Ee ae | aes) ay oleae syysnoR BmnyosIdy | = pee=|eto=|nee-|----|---=|----|----| .-2-| --<-]----|-==---|---=-- Bee re te be + + aro eS Salt es Calaeee gisueu0se10—i,, Me el elec ec) ect hee tego tee Bly || eke errr gee oe ns ie eee ee aero le Palue be |S ge | a fresees|enoeee|-eee- Cop eee ree : 2 ““"rpreqsey, A og. 7, Se hace ate Bes pee pce | oer tes mi + Scale ln eh ee gel ee gage == PS Pale eee snjo / a 4 Oy OC ay MeO ieccy lectern yar) Weta sy| sei = oP yeas SUL Re se RS gout ” es AP SAP Pest ale ig ame eho Oe Pe Cee ee eee Tpurlysy oy ok dele lel sos. eee ele | ol elce fg ear aga] ct sce pe ciate Mees cee sTTlors eumoyderq gd FI FE eS loblemlosigal | o8) os |e lak] F lad) & | of aoe ea Q. ) @|3 f Q a 5 ) ee) ee bo wR EBUEVE) 5 GeUSuleube) 2/2 |i) Ea Ee] 5 |25/ 3 | 22/35 | 28) 2F| Es pF foe | E Nae ! st a 9. a < 4 «RBBB BT o REISE eb) S| 75 FB | BE ob} me |o8| & | BE/B | Bp ies |s8 | 58 | Br! ey Pata = ba Be) EF: J be Dal ed 2 a Peas ne pa Bris at’ Gel SA] parol peel oe eee aE | LP et) eae Bese | s| * | se Bae PVE e lice sis BL ce cses) Seclcoeek B eas a . Oo Sue ol - Oo - A les “<2 : Q ee) ELE ga sel gl | el ElSE| 8 e| ” ele eget el S| ala | : 3 o og S) : ® | ° Bee ete aloe BL FL gig el Bi gl el Z| gh al : ne PES] LS] Lap ar gy FL eb] a] ad? 5 | ‘apiunjpg puv oprdojoig fo aueutnooo fo qQn7, st Diba Dirndaibii sc s00c cae ae | tg a a, Sa — Sittin atiey X ca rg eae “ a Mees Pros - a ee se i i : i gen m: : SN 2 iin ERS Sa ue ER RR iat apt 8a Mastin ya ee t s y pF ae TS a ” , ; Nr A. ae 6 - MICHIGAN FISH COMMISSION—BULLETIN NO. 5, . Pine Lake is peculiarly poor in its number of species. This is strikingly- apparent when we compare it with Intermediate Lake. Pine Lake was very thoroughly examined, and it is likely that we are acquainted with all the _ species occurring there, and yet the number is only eight. All the collec- tions from Intermediate Lake were made in one day by a party which went. down from Charlevoix and remained only a few hours, and yet the number of different forms is eleven. Intermediate Lake seems to be an unusually -. rich collecting ground, for with the exception of Lake St. Clair and Round Lake, no other lake shows such a large number of species, and both Lake St. Clair and Round Lake have been very thoroughly explored. Moreover, ‘in the case of Round Lake, several of the species may be considered as immigrants from Lake Michigan. In general it may be said that the copepod fauna of Michigan does not. differ materially from that of Wisconsin, which I have already described in a former report. (Marsh’93.) This is only what one would expect because of the very wide distribution of the species, as already noted. (Marsh ’ 93, p. 191.) ; | Inasmuch as many of the species have been imperfectly described, it has seemed best to me in preparing this paper to devote some space to. more detailed descriptions, and particularly to furnish some figures in. addition to those already published, and in this way to supplement the work of preceding papers. | The literature of the Copepoda is so scattered that it is very difficult for any one except a specialist to make determinations of species that are at all satisfactory. Without doubt this fact has deterred many from attempt-- ing any study of the Copepoda. Much valuable work in regard to the distribution of species might be done by amateur investigators if there were- any work giving brief directions by which the species might be determined with a fair degree of accuracy. This lack, with the advice of Professor Reighard, I have attempted to supply in the present paper. Preceding” the notes on Diaptomus and Cyclops, I have given a brief synopsis of the species of those genera. These synopses, which, with some modifications, are like those in my paper on the copepods of Wisconsin, are intended simply to furnish a means of recognizing the species by some of their most obvious characters. While the first six plates may be considered as sup- plementing the work of my Wisconsin paper, I have thought best, in order to aid in the identification of species to add the seventh, which repeats some of the figures of the former paper. I think that by means of the synopses and plates, any one who has the patience to make the neces-- sary dissections, will be able without much difficulty to identify our species. of Cyclops and Diaptomus, at least as far as adult forms are concerned. I have included in the synopses some species which have not yet been found in Michigan, but which have been reported from Wisconsin, and will, doubtless, after a more thorough exploration, be included in the Michigan fauna. / - a a if tes arenes 1 f d : CYCLOPIDH AND CALANID# OF MICHIGAN LAKES. 7 FAMILY CALANID2.—Grnvus DIAPTOMUS Westwoop. KEY TO SPECIES OF DIAPTOMUS FROM CHARACTERISTICS OF THE MALE. Antepenultimate joint of antenna without appendage, Fifth feet nearly equal in length, __....._..__-.-__.-_-. oregonensis. Left fifth foot shorter than right, Inner ramus of left fifth foot about equal in length to first joint of outer ramus, terminal hook of right foot Mavumnmecd ly anoular, 21 2). oe pallidus. Inner ramus of left fifth foot about twice as long as first joint of outer ramus, terminal hook of right foot with an abrupt angle at about midway of its length, Rerghards. _Antepenultimate joint of antenna with hyaline lamella, ___- leptopus. Antepenultimate joint of antenna with appendage, Appendage short and blunt, Left fifth foot hardly reaching end of basal joint of right, lateral spine of terminal joint of right foot weak, reaching about to end of joint, species large, Scene only in Spring, . 2-42 ee sanguineus. Left fifth foot reaching to about one-third the length of the terminal joint of the right, lateral spine of terminal joint large, reaching to nearly one-half the lerfoth @rgiiefenminal hook, .._._______-_-.----_--- Birget. Appendage as long or longer than the penultimate joint, Terminal hook of right fifth foot broad, lateral spine Mie minutus. Terminal hook falciform, Lateral spine nearer outer extremity of joint, ______- sicilis. Lateral spine stout, nearer base of joint, __._._____-_- Ashland. - DIAPTOMUS sIcILIs Forbes. Plate VII, figs. 1 and 11. 1882. D. sicilis Forbes, p. 645, pl. VIII, ae 9 and 20. 1884, ee Be Herrick, p. 142, pl Q; fie: 1ES93 5° 6 “ ‘ DeGuerne and Richard, p. ae figs. 13 and 14, pl. II, fig. 18. Fool wee. ee orbes, p. 702, pl. 1, fig. 6. 1893.; sige 5). = Marsh, p. 197, pl. ITI, figs, 8 and 10. D. sicilis is found everywhere in the Great Lakes, in Lake St. Clair and in the Detroit River. It is also found in Pine Lake, and very likely occurs in other bodies of water having direct connection with the Great Lakes. I do not know of its occurrence in bodies of water away from the Great Lakes, except in Green Lake (Marsh ’91 and ’93), and Lake Geneva (Forbes, 90), and both of these are deep-water lakes. Diaptomus ASHLANDI Marsh. Plate VII, fig. 2. 1893. D. Ashilandi Marsh, p. 198, pl. ITI, figs. 11-13. When I described this species in my paper on the Cyclopidew and ee of pecnemn, I knew of only two localities for it, Lake Supe- = , ee eo \ 3 LX Z Tic hy es i KS Ce NN “ee a 7 Hl ™ - ys * 7 # | a 4 hs, © z - 1 eit | gaat a ON IO eer oe eit ee gd eee See x u oh, t t j \ - ih i we Aig ml ) a fey a rok % i a PY wey Y i y pies Vie ate a Toe Tf " 5 : * f ‘ + Tae er ara poh at ray way ‘ . ‘. y ei Pr Ae eye ' nr. if Eien ; ees ise hare 8 _ MICHIGAN FISH COMMISSION—BULLETIN NO. 5. rior and Lake Erie. It occurred in the collections from Lake St. Clair ) and the Detroit River, but not abundantly. In the Lake Michigan col- lections it was acommon species, but not nearly so numerous as D. minutus. Ifound it in none of the smaller lakes except Round Lake and. Pine Lake. Diaptomus minutus Lilljeborg. Plate VII, fig 3. 1889. D. minutus DeGuerne and Richard, (Lilljeborg) p. 50, pl. I, figs. 5, 6 and 14, pl. ITI, fig. 25. 1891. D. sicilis var. imperfectus Forbes, p. 703. “1891. “ \ws"NRarsh, p. 212. 1893.,. “\ “Marsh, p. 199, pl. TV, figs. 1 to 3. D. minutus is, perhaps, the most common of all the Diaptom in the collections from Lake St. Clair and the Great Lakes. With D. sicilis and — D, Ashlandi it forms the great bulk of the crustacea in the limnetic col- lections. While I have found it in one or two of the Wisconsin lakes, it, like the two preceding species, has not so far been found in any of the Michigan waters which do not have direct connection with the Great Lakes. The three species may be fairly considered as cheragtaaeee of the — ty of the Great Lakes. It is with considerable hesitation that I have considered Forbes’ s 7mper- — . fectus identical with minutus. One can not be certain of the identity of _ the two forms from the description given by Forbes, and yet from the localities which he gives for his variety, it seems very probable that the two are the same. He speaks of it as common in Lake Superior and Lake Michigan, and in some adjacent lakes, and in Lake Geneva. Inasmuch as D. minutus is s0 common in the Great Lakes it is not at all probable that it has been overlooked by so accurate an observer as Profes3or Forbes, and as he reports amperfectus as an abundant form, I think the p-obabili- ties are that imper ‘fectus 1 is a synonym of minutus. DIaPTOMUS OREGONENSIS Lilljeborg. Pye Pilate VII, fig. 5. (1889. D. oregonensis DeGuerne and Richard, (Lillj.) pl. I, a 5, pl. 1, fig. 8. 1893.“ i Marsh, p. 200, pl. IV, figs. 4 and 5. _ D. oregonensis is the common limnetic species of the smaller lakes. It occurs in the Great Likes, but not abundantly, while in the smaller bodies ae of water it usually forms the larger part of the limnetic es * CYCLOPIDH AND CALANID OF MICHIGAN LAKES. 9 Diaptomus REIGHARDI, sp. nov. Plate I, figs. 1-4. The first segment of the cephalothorax is considerably shorter than the second. The first two segments form nearly half the length of the cepha- lothorax. The last segment is armed behind with two very minute spines. The first segment of the abdomen of the female is elongated, nearly equal in length to the remainder of the abdomen and the furca. It is dilated laterally and in front and bears two rather small lateral spines. The second segment is about one-third shorter than the third. The third _ segment is slightly shorter than the furca. The antennae reach the end of the furca. The right antenna of the male is swollen anterior to the geniculating joint; the antepenultimate joint has no appendage. The outer ramus of the fifth foot of the female is two-jointed. The third » joint is represented by the customary two spines. The inner ramus is one-jointed; it is somewhat longer than the first joint of the outer ramus, and is armed at tip with minute setz and two spines. In the right fifth foot of the male the basal joint is quadrangular, about one-half longer than broad. The length of the first joint of the outer Tamus is about equal to its width. The second joint is elongate, concave on its inner margin; at about one-third of its length there is a minute spine on its inner margin; the rather long lateral spine is situated at about two thirds of its length. The terminal hook has a single abrupt angle at about one-half its length. The inner ramus is one-jointed and equals in length the first joint of the outer ramus. The left fifth foot of the male reaches a little beyond the middle of the second joint of the outer ramus. The basal joint is about as broad as long, and is somewhat shorter than the basal joint of the right foot. The - first joint of the outer ramus is about as broad as long, its distal end con- siderably narrower than the proximal. The second joint is about twice as long as the first, and the tip is expanded into two finger-like processes, of which the outer is much the larger and is armed on its inner surface with a pad bearing minute sete. The inner ramus extends to rather less than one-half the length of the second joint of the outer ramus. Length of female, 1.1395 mm.; male, 1.0248 mm. This species, which is nearly related to D. oregonensis, is yet readily dis- tinguished by the characters of the male fifth foot. I found it in the collections from only three localities,—the North Lake on Beaver Island, Intermediate Lake, and Crooked Lake. I have named this species in honor of Professor Reighard who has, directly and indirectly, done so much to increase our knowledge of lacus- trine faune. 2 ¥ x 10 MICHIGAN FISH COMMISSION—BULLETIN NO. 5. Genus EPISCHURA Forsss. Plate II, figs. 1-6. Plate III, figs. 1-6. HipPIscHURA LACUSTRIS Forbes. 1844. Scopidphora vagans Pickering, p. 62. 1882. EH. lacustris Forbes, pp. 541 and "648, pl. VIII, figs. 15, 16, 21, 23, pl. IX, fig. 8. 1884. Eh. lacustris Herrick,p. 131, pl. Qo fe: 13) 1889. ig DeGuerne and Richard, p. 90, pl. LV, figs. 3, 9 and 10. Soe.“ c Forbes, p. 704, pl. I, figs. 15; pl. Il, fig. i 1895.4 s Marsh, e “200, ‘pl. IV, fig. 6. I have very littie doubt that, as stated by Herrick (’84, p. 181), the Scopiophora vagans of Pickering is the same as LE. lacustris. The state- ment in regard to the armature of the abdominal furcee can apply to no other genus, and as only one species of Epischura has been found in the Great Lakes, there would seem to be little doubt as to the identity of Pick- ering’s species. If then we follow the laws of priority as strictly as do. some authors, we should throw out Forbes’s name. But I cannot think it wise when a name has been so long incorporated in our literature, and is. founded on an accurate and easily recognized description, to throw it aside - in favor of a name accompanied by a description which, it is true, probably applies to this animal, but is manifestly inaccurate in some particulars, and may be in all. It is not necessary to give a detailed description of this species, as that has already been done by other authors, but, as very few figures of it have been published, it has seemed best to me to draw quite a number in order > that they may serve for comparison of this genus with others, and of the various species of H’pischura with each other. A few points in the anatomy, which have not been noted by others should be mentioned. Forbes has recently (’93, p. 255) called attention to the fact that the. fourth abdominal segment of the male is without a process, and that the fifth bear§ two processes. The antenne are 25-jointed. In the female, clavate sensory setze are present on all segments except the 4th, 6th, 8th, 10th, 20th, 21st, 22d and (24th. The 8th and 11th segments have each a short spine. The left. antenna of the male is like those of the female except that the sensory setze are much longer, particularly on the basal segments. The right antenna of the male is 22-jointed, with a hinge between the 18th and 19th segments. The 19th segment is formed by the union of the 19th, 20th and 21st of the typical antenna, and the 20th by the union of the 22d and 23d. The outer rami of the swimming feet are three-jointed, and the inner ‘one-jointed. In all the feet the inner ramus bears five sete. In the first foot the first and second joints of the outer ramus have each one external — and one internal seta. The terminal joint has six sete. In the second, third, and fourth feet, the first and second joints of the outer ramus have spines externally instead of sete as in the first foot. The terminal joint has two short spines externally, a long terminal spine with its outer margin deeply serrate, and four sete on the internal margin. 3 Lake Michigan, and many of the smaller lakes. ~ -—s« CYCLOPIDA] AND CALANIDA! OF MICHIGAN LAKES. 11 E. lacustris was a common species in the collections from Lake St. Clair,. ‘, Genus LIMNOCALANUS Sars. LIMNOCALANUS MACRURUS Sars. Plate IV, figs. land 2, Plate VY, figs. 1-5. 1863. L. macrurus Sars., pp. 228-229. 1882. i Forbes, p. 648. 1886. Centropages Grimaldi DeGuerne, pp. 1-10. 1885. L. macrurus Nordqvist, pp. 31- 37, pl. I, figs. 9-11; pl. II, figs. 1-5; pl. II, figs. 1-4. 1889. L. macrurus DeGuerne and Richard, p:77,- ‘pl. EV, fies. 5; Tie and 12. 1891. JL. macrurus var. auctus Forbes, p. 706. Tego. eS Marsh, p. 201, pl. LV, fig. 7. For the description of L. macrurus we must depend largely upon the- elaborate description and figures of N ordqvist. Forbes (’91, p. 706) thinks that our form is sufficiently different from the European to rank as a distinct variety. When preparing my former paper (’93) it did not seem to me that there was good reason for establish- ing a new variety. Recently I have made a more careful examination of the details of its structure, using material from Detroit River, Lake Mich-. igan, and Green Lake. So far as the specimens I have examined are con-. cerned, the points of difference mentioned by Forbes (791, p. 707) do not- exist. It seems to me that the twenty-fifth antennal segment is clearly separated from the twenty-fourth, and not consolidated as stated by him. _ In ali my specimens I find the hook like spines on the eighth and twelfth _ segments. Nordqvist and Forbes are in agreement in regard to the terminal teeth. of the mandible, but Forbes finds one seta instead of the two figured by: Nordqvist; in this respect my observations confirm those of Forbes. The accessory spines have been evident in my preparations. It would seem then, that unless L. macrurus is susceptible of local variations—a highly | improbable supposition—that Forbes’s variety can not stand, for the only point of difference on which it rests is the existence of one seta on the mandible instead of two. The second joint of the second maxillipede differs slightly from Nord-. qvist’s figure, and I have accordingly figured it. (Pl. V, fig. 5.) The . difference appears to me, however, unimportant. It is impossible to tell whether our species may not differ from the. _ European in the armature of the antenna, as that was not worked out in detail by Nordqvist. In regard to the sensory sete, he simply states that they are present on some of the segments, but does not state their number. _ In the female, clavate sensory setz are present on all joints except the. 4th, 20th, 21st, 22d, and 24th. The setx are distributed as follows: the- first joint has three; there are two on the 2d, 3d, 5th, 7th, 9th, 10th, 11th 18th to 19th inclusive, and 22d to 24th inclusive; the Ath, 8th, 12th 20th,. ‘ 4 y oe 7 { 12 MICHIGAN FISH COMMISSION—BULLETIN NO.5. and 21st have one seta; the 6th has none; the 25th has four set, one of | which is plumose; the ‘8th and 12th have, i in addition to the ordinary and “sensory sete a hook-like spine. “ee The left antenna of the male is armed like the female antenna. a. The right antenna of the male is 22-jointed, the 19-21 being united in one, and the 22d and 23d. The joint is between the 18th and 19th. - The side of the 17th is produced into a blunt spine, and the 18th and 19th are armed | on the inner margin with rows of minute spines. The number of the sensory sete: is the same as in the left antenna and in the antenna of the female, — and not greater as stated by Nordqvist. In fact the differences in the armature of the right and left antenne are only apparent, and are occa-_ - ssioned. by the coalescence of the 19th—21st and the 22d and 23d joints. ; It has seemed best to me to figure the swimming feet and describe them > in some detail, in order to get a basis of comparison with similar forms. In the first foot both the first and second basal joints are armed inter- — mally with a plumose seta. The first two joints of the exopodite have no — external spines; the terminal joint has two external spines, two apical sete—the outer spinulose on its outer margin—and three internal sete. ‘The terminal joint of the endopodite has one internal seta, two apical, and three internal. The second, third and fourth feet have no seta on the second basal joint, and the first and second joints of the exopodite have each an external spine. — In all the feet except the first there are groups of two or three minute spines at the bases of the spines of the exopodite. . The second and third feet are alike. The terminal joint of the exopo- — ‘dite has four internal setz, and the terminal joint of the endopodite has two external sete and four internal. The fourth foot is like the second and third except that the terminal cae joint of the endopodite has three internal sete. The fifth feet have no | setze on the basal joints. The second joint of the exopodite in the female | is prolonged internally into a hook-like expansion. The exopodites of the | male are two jointed, the terminal joints having a peculiar construction {| ‘more easily understood from the figure than from any written description. The terminal joints of the endopodite in both male and female are armed ‘with two external, two apical, and two internal sete. | FAMILY CYCLOPID@.—Genus CYCLOPS Mutter. ' ) KEY TO SPECIES OF CYCLOPS. Antenne 17-jointed, Fifth foot one-jointed, weed with one spine and two : long setee—a large species of dark color, _____._-_.--- | ater. | Fifth foot two-jointed, eles Second joint of fifth foot armed with seta and short 7 spine, Merman joint of outer branch of swimming feet armed externally with three spines, Furca of moderate length—occurring in pools, ___- Americanus. Furca elongated, outer furcal seta abbreviated to a short, thick spine—limnetic in habit, ___.____-- brevispinosus. CYCLOPIDAl ‘AND CALANIDA OF MICHIGAN LAKHS. Page Terminal joint of outer ramus of swimming feet armed externally with two spines, _--__---------- parcus.. _ Second joint of fifth foot with two terminal sete, Furea. short—occurring in pools,__________.-_--_-- NAvUS. y Furca elongated—limnetic in habit, ---_----------- pulchellus. Second joint of fifth foot with one terminal and one : EC USESDAL’ 476) (2c Geum les CAMEO Sy FoR eM nck ay ae Mn rg at ie Leuckartt.. — ba Second joint of fifth foot with three sete, | ey With clavate seta on twelfth antennal segment, | he inner margin of furca not beset with Le ege- | eos sacs lying away from abdomen, ___--__--:-~---- albidus. — | Sensory hair on twelfth antennal Sa enk: inner margin of furca beset with hairs, egg-sacs close 7 Hy NOTION fe Spe Ny Le NO Ne eed gee Suscus.. Antenne 16-jointed, fifth foot three- JORMbe ie ENA Ca BSN Sa modestus. | Ai itis 12-jointed, fifth foot one-jointed, } Furca variable in length, armed externally with a row of ie ee priRen ies wm ee Ose ue Oe serrulatus. i; Furca short, without armature of spines—a small limnetic | oe eres Moe aN el A A Wind we SE Jluviatilis. _ Antenne 11-jointed, 3 : 4 Sememminc feet S-jointed; 5/2 se ee phaleratus. : Swimming feet 2-jointed, ______________-_ sags win gy eee tS bicolor. Membmreeere er O1NeCU) a Se ee ed ee et jimbriatus. f N ~ Cyctors ATER Herrick. Plate VI, figs. 1-4, 6, and 12. - 1882. C.ater Herrick, p. 228, pl. III, figs. 9-12. Pagar | tS rs p. 145, pl. Q, figs. 9-12. Te a , The cephalothorax is oval, nearly as broad as long, with the lateral angles produced caudally. The first segment equals two-thirds the total length of the cephalothorax. _ The antennz are 17-jointed, about as long as the cephalothorax, its seg- _ ments having the typical armature of the Cyclopide. The last two seg- ‘ments have a smooth hyaline lamella, which in the last segment projects as a flat, blunt process beyond the end of the joint. The abdomen is of moderate length, the last segment being armed posteriorly with a row of fine spines. The furca is rather more than twice as long as its width. The lateral spine is situated near the end. Of the - if b 4 ‘ terminal sete, the outer is slightly shorter than the inner, the second is , about twice as long as the outer, and the third about three times as long. P The swimming feet are armed as follows: : FIRST FOOT. eS _ Outer br. ex. 3 spines. Inner br. ex. 1 seta. | ee a % ap. 2 sete. ap. 1 spine, 1 seta. in. 3 sete. in. 3 sete. 14 MICHIGAN FISH COMMISSION—BULLETIN NO. 5. SECOND AND THIRD FEET. Outer br. ex. 3 spines. Inner br. ex. 1 seta. | ap. 1 spine, 1 seta. ap. 1 spine, 1 seta. in. 4 setee. ‘in. 3 sete. FOURTH FEET. Outer br. ex. 2 spines. Inner br. ex. 1 seta. ap. 1 spine, 1 seta. ap. 2 spines. in. 4 sete. in. 2 sete. \ The fifth foot is one-jointed, and armed with a stout spine and two long sete. Average length 1. 77 mm. | A large, very robust form, of striking appearance because of its deep colors. The colors of the St. Clair specimens were as follows: antennz, — antennules, swimming feet and furcal sete dark blue, almost black. The caudal margins of the cephalothorax have the same color. On each side of the abdomen, and extending to the ends of the furce is a strip of the © same color but darker. Borders of the cephalothorax tinged with green. Oviducts white. The ovary is orange. 2 _ To the naked eye it resembles closely in form, size, and color an Arre- nurus with which it is found associated. This may be a case of poe | mimicry. This species was originally described by Herrick in 1882, and is men- tioned by him in his succeeding reports of 1884 and 1887, but has been noted by no other author. It was discovered by Professor Reighard in the St. Ciair collections, and was worked out very thoroughly by him. It is from his notes that the above description is taken. i This seems to be a somewhat rare form in this region. I have found a few individuals in Rush Lake, Wisconsin, and in Michigan, besides in the St. Clair collections, have found it in Twenty-Sixth Lake, Intermediate Lake and Susan Lake. Where it occurs it is easily detected because of its large size and prominent colors. The specimens from Round Lake had more of the red color, so much so that this, on a superficial examination, — seemed to be the most prominent color. : CYCLOPS BREVISPINOSUS Herrick. Plate VII, fig. 12. 1884. C. br evispinosus Herrick, p. 148, pl. 8, figs. 7-11. 1893; =‘ Marsh, p. 205, ‘pl. IV, figs. 11 and 12. C. brevispinosus occurred in the collections from Lake St. Clair, the Detroit river, Lake Erie, Susan Lake, Beaver Island, Intermediate Lake and Round Lake. I have found it in collections from Lake Superior and Lake Ontario, but, curiously, never in Lake Michigan collections. gees Pi a fT Le ee = | y CYCLOPIDA AND CALANIDZ OF MICHIGAN LAKKS. 15 beens SOP, OO gd CycLors —- ——_ Plate VII, fig. 14. 838" Cy pulchetiusKeeh,-H-; 2t, pt-2>- " 1857. nos “3 bicuspidatus Claus, p. 209, pl. XI, figs. 6 and 7. ' 1863. . 101. 1863. “ pulchelius Sars, p 246. v 1870. e | bicuspidatus Heller, pyc: ( 1872. Fric, p. 221, fig. 6. (1876. “ ef Hoek, p. 17, ai I, figs. 7-11. ‘1880. “ pulchellus Rehberg, p. 543. 1880. ‘“ helgolandicus Rehberg (’80a), p. 64, pl. IV, fig. 5. 1882. ‘* Thomasi Forbes, p. 649, pl. IX, figs. 10, 11, and 16. 1883. ‘“ pectinatus Herrick, p. 499, pl. VIL, figs. 25, 28. 1883. “ Thomasi Cragin, p. 13, pl. III, figs. 1--13. 1884, “ ra Herrick, p. 151, pl. U, figs. 4, 5, 7, and 8. shape: $s « pulchellus Daday, Ds. 220. 1886. _ Vosseler, p. 194, pl. V, figs. 19-28. 1590...“ as Lande, p. 50, pl. MX, figs. 146-155. 1891. “ Thomasi Forbes, p. 707, pl. II, fig. 8, 1891. “ bicuspidatus Brady, p. 18, pl. V, figs 1-5. 1891. “ Thomasi Brady, p. 14, pl. VI, figs. 1-4. fc] in bicuspidatus Schmeil, p. 27. fear Richard, p. 229, pl. VI, fig. 6. to yi e sis Schmeil, p. 75, pl. deli fig s. 1-3. 1893. ‘“ Thomasi Forbes, p. 249, pl. KRKEX, oa 9-12, pl. XL, fig. 13. 1893. “ pulchellus Marsh, p. 207, pl. LV, figs. 18-19. . C. pulchellus is the common Cyclops of the Great Lakes. It occurs ~ sometimes in smaller bodies of water, but in the collections from Michi- gan I have not found it from any of the small lakes except Pine Lake and Round Lake. According to Forbes (82 b) C. pulchellus and. the Diaptomi form the greater part of the food of the young white fish. Cyctors Pparcus Herrick. 1882. C. parcus Herrick, p. 229, pl. VI, figs. 12-15. / 1884. “ p. 148, pl. R, fig. 22. preteen a Marsh 9: 208, pl. LV, fie. 16; pl: Vy aig. Wi: I have found C. parcus eee in the collections from Lake St. Clair. CYCLOPS LEUCKARTI Sars. Plate VII, fig. 15. 1863. C. Leuckarti Sars, 239. 1874. “ simplex mee ead p- 70, pl. XV, figs. 1-3. 1875. “ tenwicornis Uljanin, p. 30, pl. IX, figs. 12 and 13. 1876. ‘ Leewwenhoekii Hoek, p. 19, pl. III, “figs. 1-12. 1880. .“ simplex Rehberg, p. 542. . 1884. nF 7 Herrick, p. 150. iG 1884. 1885. 1885. 1885. 1886. 1887, 1890. 1890. <5, BSOT. bikes) 1891. 1891. 1892. 1893. MICHIGAN FISH COMMISSION—BULLETIN NO. 5. # 4 CG ol honpides Herrick, p. 150, vr S, figs. 2-6. ‘“* Leuckarti Daday, p. 218. - simplex Daday, p. 236. ‘“* pectinatus Daday, p. 223, pl. I, figs. 7-13. ‘“ sumplex Vosseler, p. 198, pl. LV, figs. 15-17. . oa berrieks aan i ie pl. VEL, fies 1, ay: - Thallwitz, p. 79. ) i ‘| uande, p. BS, pl. XVI, figs. 42-45; pl. XVII, figs. 46— 50. “ Leuckarts Schmeil, p . 25. | ‘“* edax Forbes, p. 709, al ITI, fig. 15; pl. a figs. 16-19. “* Scourfeldi Brady (2) pO; pl Py: ‘figs. 1 8. : “~ Leuckarti Richard, p. 230, ‘pl. VI, ‘fig. 20. - Schmeil, p. 57, vl, ta: ‘figs. 1-8. fe Marsh, p. 209, pl. IV, fig. 17; pl. V, figs. 2-6. I have no doubt that, as stated by Schmeil, C. Leuckarti Claus and C. Leuckarti Sars are identical, and that possibly by strict laws of priority Claus should be given as authority for the name. Yet, as the description by Claus is not only imperfect, but in many respects inaccurate and mis- leading, I have preferred to retain the designation of C. Leuckarti Sars. Other points in the synonomy are discussed in Schmeil ’92 and Marsh ’93. As would be expected, this species was distributed almost universally in the waters examined. 1820. 1841. 1850. 1857. 1863. 1863. 1865. 1870. — 1872. 1876. 1878. 1882. 1884. 1885. 1886. 1888. 1890. 1890. i891. 1891. 1891. 1892, 1893. CycLops Fuscus Jurine. Plate VI, figs. 5, 7 and 11. Monoculus quadricorms fuscus Jurine, p. 47, Bh Il fie. ee C. signatus Koch, H 21, pl. VIII. “ quadricornis var. ¢ Baird, p. 203, pl. XXTYV, fig. 5. “ coronatus Claus, p. 29, pl. A fig. 5, and pl. IT, figs. 1-11. st up. ON; pl: LL, fies 16; yl fies signatus Sars, p. 242. “ coronatus Lubbock, p. 199. i: fs Heller, p. 71. . i Fric, p.: 218, fig. 12. ig 2 Hoek, p. 12. ‘ signatus Brady, p. 100, pl. XVII, figs. 4-12. “ fenwicornis Herrick, p. 227, pl. V, fig. 14; pl. VI, ae 1-11, and 20. “ tenuicornis Herrick, p. 153, pl. BR, fig. 16; pl. Q’, figs. 8-11, and 20. “ signatus Daday, p. 208. Vosseler, p. 159, pl. LV, figs. 6-10. fuscus Sostarig, p. 58. signatus Thallwitz, p. 79. a 2 Lande, p. 33, pl. XV, figs. 1-12. ee cS i Brady, p. 6, pl. 2, fig. 5. ‘« fuscus Richard, p. 293, pl. VI, fig. 6. i fe Schmeil, p. 22. a “ p. 123, pl. I, figs. 1-7b; pl. LV, fig. 2. signatus Marsh, p. 211. 5 fi 4 TR ok CA oan Ue , ' Ni 7 ae - CYCLOPIDA AND CALANIDA OF MICHIGAN LAKES. 17 _ In my paper on the Wisconsin Cyclopide: and Calanide (’93), agreeing with Herrick and Brady, I expressed my belief that the two forms here called fuscus and albidus, the coronatus and tenuicornis of Claus, belonged to the same species, fuscus being the more mature form. Since writing _ that paper I have examined a large number of specimens from widely | separated localities, and I must acknowledge that I was wrong, and that, as stated by Schmeil (92), the two forms must be considered distinct, for 1 have been utterly unable to find the connecting forms. The points of dif- ference, as stated so elaborately by Schmeil, hold good for the American specimens. C. fuscus has a sensory hair on the twelfth antennal segment, the hyaline lamella of the 17th segment deeply notched, the third segment of the antennule short, the inner borders of the furca thickly beset with hairs, and the egg sacs lie close to the abdomen, while C. albidus has a clavate seta on the twelfth antennal segment, the membrane of the 17th segment serrate or smooth, the inner borders of the furca either without ; Kuropean type. hairs or with only fine hairs, and the egg sacs lie separated from the abdo- men. These characters, with the greater size of C. fuscus, serve to dis- tinguish the species, while the less evident characters mentioned by Schmeil are easily demonstrated. One characteristic not mentioned by Schmeil I have found constantly in my specimens. The larger of the two terminal spines of the endopodite of the fourth foot, instead of being serrated on its edges as is customary in all the spines of the swimming feet, is beset on its inner margin with long, rather irregular teeth, as shown in the plate. (Plate VI, fig. 7.) If this peculiarity exists in the European forms, it would seem probable that it would have been noted by some observer, but I have nowhere seen an account of it. It may serve then to indicate a slight variation from the have found C. fuscus in the Michigan collections from only one locality, Intermediate Lake. 1 have found it in several Wisconsin locali- ties, though nowhere abundantly, and it is probable that it occurs in-other localities in Michigan. CycLOPsS ALBIDUS Jurine. Plate VI, figs. 8-10. 1820, Monoculus quadricornis albidus Jurine, pp. 44 and 47, pl. II, figs. 10 and 11; pl. IIT, fig. 24. 1841. C. annulicornis Koch, H SL. pe. Ve. 1850. ‘“ quadricornis var. b Baird, p. 202, pl. XXIV, fig. 4. 1857. ‘“ tenwicornis Claus, p. 31, pl. ITI, figs. 1-11. 1857. “ pennatus Claus, p. 35, pl. ITI, figs. 12-17. 55 Neale pene Claus, p. 99, pl. T, fie. 33, pl; Ly ‘fies 17; pha g. 5. 1863. “ tenwicornis Sars, p. 242. 1863. “ annulicornis Sars, p. 243. . 1863. “ tenuicornis Lubbock, p. 202. 1870. “ tenwicornis Heller, p. 71. 1873. °“ s Fric, p. 219, fig. 12. 1874. “ Clausit Poggenpol, p. 70, pl. XV, figs. 4-14. 41875. =“ signatus Uljanin, p. 29, pl. NG figs. oe 11; pl XI, fig. 8. 1876. v “‘ Hoek, p. 12, pl. I. figs. 1-4, 18 | MICHIGAN FISH COMMISSION BULLETIN NO.5. ~~ 1878. C. tenuicornis Brady, p. 102, pl. XVII, figs. 1-10. 1882. Herrick. 1883. i o Cragin, p. 3, pl. I, figs. 1-14. 1883. “ signatus var. fasciacornis Cragin, p. 2, ple: fee 15. 1884. “ tenwicornis var. a Herrick, p. 153, pl. Q’, figs. 1-7. 1885." << . Daday, p. 211. 1886.“ - Vosseler, p. 189, pl. IV, figs. 6-10. 1888. ‘ albidus Sostarie, pl. ie figs. 3, 4 and 12. 1890. “ tenwicorns Thallwitz, p. 79. 3 S90. ch Lande, p. 36, pl. XVI, figs. 22-82. x 1891. “ gyrinus Forbes, p. 707, pl. II, fig. 9° pl. ITI, fig. 14. 1891. “ albidus Schmeil, p. 23. 1891. “ annulicornis and jeninenes Richard, pp. 224-226. 1892. ‘ albidus Schmeil, p. 128, pl. I, figs. 8-14b; pl. IV, fig. 2. 1893. ‘‘ signatus Marsh, p. 211, pl. V, figs. 7-9. Schmeil states that the antennz of C. albidus are armed with crowns of spines as in the case of C. fuscus. This seems to be rarely true in our forms. Although I have examined with great care large numbers of mature females, it is only in very few specimens that I have found this peculiar — armature. The membrane of the terminal antennal segment is ordinarily serrate. The common form corresponds to the annulicornis of Sars and Richard, which, according to Schmeil, Richard now allows to be a variety of albidus. The distinguishing characteristic of annulicornis is the rudi- mentary seta of the inner margin of the terminal segment of the endopo- dite of the fourth foot. This is represented in most of my specimens only ~ by a minute spine. (Pl. VI, fig. 9.) In two individuals I have found in place of this minute spine a short seta. (Pl. VI, fig.8.) In these two speci- mens the circlets of spines were present on the 8th, 9th, 10th, 12th, 13th, and 14th segments. It was this form evidently that Cragin called C. tenuicornis (’83 pl. II, figs. 1-14), as is shown very clearly by the figures of the fourth foot and antennule, although he did not figure the circlets of spines on the antennal segments. C. signatus var. fasciacornis Cragin, it is not possible to identify with certainty, although it seems probable that it is albidus. C. gyrinus Forbes does not have the antennal circlets of | | spines, but does have a short seta instead of a minute spine on the fourth foot, thus agreeing with Cragin’s figures of C. tenwicorms. This would seem to be intermediate between the two forms Ihave seen. It isdifficult — in such a case to tell just where the limits of species should be drawn, for we are entirely ignorant of the life histories of the forms, and it is certain that the Cyclopidw have wide limits of variation. It seems to me safer, for the present, at least, to consider such minute differences as varietal, and not to increase the number of species. _ C. albidus is not very abundant, but occurred in many of the St. Clair collections, and in some of those from other points in Michigan. It isa universally distributed species, but does not occur in great numbers. _CYCLOPS FLUVIATILIS Herrick. 1882. C. fluviatils Herrick, p. 231, pl. VII, figs. 1-9. 1883. ‘“ magnoctavus Cragin, p. 5, pl. II, figs ie 18S4.° °* (fluviatilis Herrick, p. 159, pl. Q’, gee —9, 1887. a Herrick, p. 15. ree yo / CYCLOPIDA AND CALANIDZ OF MICHIGAN LAKES. 19 S915. eae Brady, p. 19, figs. 1-4. 1893. “ fluviatilis Marsh, p. 214, pl. V, figs. 14 and 15; pl. VI, fig. I. C. fluviatilis occurs in most of the limnetic collections in all except the smallest bodies of water. CYcLOPS SERRULATUS Fischer. 1851. C. serrulatus Fischer, p. 423, pl. X, figs. 22, 23, 26-31. pedigoa.. |“ Lilljeborg, p. 158, pl. XV, fig. 12. eat, % Claus, p. 36, figs. 13. puloop...“* ib Sars, p 254. PS65.. |“ ‘ lass p. 101, pl. I, figs. 1 and 2; pl. IV, fig. 12; pl. XI, fig. 3. 1863. “ s Lubbock, p no. SOE 3,6 me Heller, p. 72, Hohe. x Fric, p. 222, fig. 18. Neos “8 Uljanin, p. 34, pl. VIII, figs. 1-8. L578, . Brady, p. 109, pl. XXII, figs. 1-6. W783.“ i var. montanus Brady, p. 110, pl, XXII, figs. 7-14. PSB0.: .* agilis Rehberg, p. 545. 1882. “ “Forbes, p. 649. 1882. “ serrulatuws Herrick, p. 230, pl. V, figs. 1-5; pl. VII, fig. 10. 1883. “ wpectinifer Cragin, p. 6, pl. IV, figs. 1-7. 1884. “ serrulatus Herrick, p. 157, pl. O, figs. 17-19. , 1884, “ 4 var. elegans Herrick, p. 158. 1885. . “ agilis Daday, p. 240. aEpeby « <* “ Vosseler, p. 190, pl. V, figs. 29-31. HOO): . Thallwitz, p 19. ASO0e: ** ‘‘ Lande, p. 60, pl. XVII, fig. 69; pl. XVIII, figs. 70-80. 1891. “ serrulatus Schmeil, De 20: beg * “ Richard, p. 234, pl. VI, figs. 6-12. 1891. ‘ agils Forbes, p. 710. 1892. “ serrulatus Schmeil, p. 141, pl. V, figs. 6-12. Pieboge.. »-* ig Marsh, De 215, pl. VI, figs. 2-5. This well known species occurs everywhere i in Michigan waters and with the same variations in structure which I have noted in the collections - made in Wisconsin. (Marsh 93, pp. 215-216.) CyYcLOPsS PHALERATUS Koch. 1838. C. phaleratus Koch, H 21, pl. IX. 1851. canthocarpordes Fischer, p. 426, pl. X, figs. 24, 25, 32-38. 18533) Lilljeborg, p. 208. ce Cais es Claus, p. 37, pl. I, figs. 6-10. 1863. " SE OF 102, pl. IV, figs. 1-4. lis] Pua fe Lubbock, p. 202. 1863. ‘“ phaleratus Sars, p. 255. 1872. “ canthocarpoides Fric, p. 223, fig. 19. 1874. “ eo behe Poggenpol, p. 72, pl. XV. figs. 22-24; pl. XVI, figs. 7 and 8. 1875. “ phaleratus Uljanin, p. 38, pl. TX, figs. 1-5. Lyell ts aaa i <. brady, p. 116, “pl. oenin figs. 7-13. ~ 1882. ‘“ adolescens Herrick, p. 231, pl. VI, figs. 15--20. f : . ; x ; ‘ he Pe RV %, as | b * Se HEN Ms eee ah aie i my r ee - yf" 1 oe , ian A Tee 20 MICHIGAN FISH COMMISSION—BULLETIN NO. 5. 1883. ©. perarmatus Cragin, p. 7, pl. I, figs. 9-18. 1884. “ phaler atus Herrick, p. 161, pl. R, figs. 6-10. S85: Daday, p. 252. 1887. “ = iemiek; p. 14, pl. VII, figs. 2, a-d. 1888.“ s Sostarig, p. 74, pl. II, figs. 21-29, — S90... °K ‘ Lande, p. 75. pl. XX! figs. 126-136. LSOE Schmeil, p. 36. Pool. . Brady, p. 25, pl. IX, fig. 2. She Mf Richard, p. 238, pl. VI, fig. 12. M802...‘ a Schmeil, p. 170, pl. VIII, figs. 1-11. SOB. < Marsh, p. 216, pl. VI. figs. 6 and 7. I have found C. phaleratus in the collections from only three localities,— Lake St. Clair, Intermediate Lake, and Twenty-sixth Lake. Very little -attention, however, was paid in the collections to the smaller lakes and stagnant pools, and it is probable that in such localities it occurs generally distributed through the State. CyYCLOPS, BICOLOR Sars. Plate I, figs. 5-7. 1863. C. bicolor Sars, p. 253. 1880. ‘“ oe Rehberg, p. 547. 1884. “ Herrick, p. 160, pl. R, fig. 12. 1885. “ Daday, p. 246. 1885. “ brevisetosus Dads, p. 255, pl. IIT, figs. 3, 5 and 10. Tens eth diaphanus Herrick, p. 16, pl. VII, figs. 3 a-e. 1388; 2 °° Lande. p. 67, Be 18, figs. 91-98. 1891. “ bicolor Schmeil, p. 34. 1891. “ diaphanus Richard, p. 236, pl. VI, fig. 26. 1892. ‘ bicolor Schmeil, p. 118, pl. VI, figs. 6-13. HG Bee OG a Marsh, p. 217. I have found C. bicolor in the collections from three of the Michigan lakes—Lake St. Clair, Intermediate Lake$ and South Lake on Beaver Island. Doubtless more thorough collections from small lakes and stag- nant pools would furnish other localities, though this species seems to be nowhere very abundant. I have found, in a collection from a lake in © northern Wisconsin, an egg-bearing female with ten-jointed antenne, the fourth and fifth joints of the eleven-jointed variety being united in one. Unless this specimen should be considered a monstrosity, we would infer that this species can reproduce in either the ten or eleven-jointed stage. I have added to the synonomy as previously given C. brevisetosus Daday. I do not feel certain of the identity of the two forms, and yet it seems to me probable that they are the same. I can not read the Hungarian, but from the Latin synopsis and the figures I can not help thinking that brevisetosus is the same as bicolor. The points of difference are the fol- lowing. The furca of brevisetosus is longer than in typical bicolor. The armature of the swimming feet does not correspond to Daday’s description, but the one figure which he gives of a swimming foot closely resembles the structure of bicolor, and does not correspond to his own description. The antennz of brevisetosus are ten-jointed, but they correspond exactly to — the structure of my ten-jointed specimen of bicolor. In all other respects the descriptions agree. , - CYCLOPID AND CALANID# OF MICHIGAN LAKES. _ 21 BIBLIOGRAPHY. Although the list of papers consulted is very nearly the same as that of my paper on the Wisconsin Cyclopide and Calanida, I have though it best to insert it in this paper for convenience of reference. I have not _ had the opportunity of seeing the original paper of Poggenpol, nor the - papers of Sostaric and Thallwitz, and the quotations from those authors are taken from Schmeil. In all other cases [ have personally verified the references. Barrp, W.: 50. Natural History of the British Entomostraca. Ray Soc., Lond. Brapy, G. S.: 78. Monograph of the free and semi-parasitic Copepoda of the Brit- ish Islands, 3 vols., Ray Soc., Lond. 91. Revision of the British Species of Fresh-water Cyclopide and Calanide. Natural History Transactions of Northumberland, Durham and Newcastle-upon-Tyne, Vol. XI, part 1. Cuaus, C.: rT se 57. Das Genus Cyclops u. s. einheimische Arten. or Archiv. fur Naturgeschichte, XXIII, 1 Bd., pp. 1-40. 63. Die freilebenden Copepoden mit besonderer Beriicksichtigung - der Fauna Deutschlands, der Nordsce und des Mittelmeeres. | Leipzig. Crain, F. W:: 83. A Contribution to the History of the Fresh-water Copepoda. - Trans. Kans. Acad. Sci., Vol. VIII. Dapbay, Jeno.: °85.. Monographia Kucopepodorum liberorum in Hungaria hucusgue repertorum. A. M. tudomanoys Académia 4ltal a Vitéz-alapbol. DeKay, J. E.: 44, Zoology of N. Y., VI, Crustacea. _ Fiscuer, 8.: Bt 5158. Beitrage zur Kenntniss der in der Unecisia von St, Peters- burg sich findenden Cyclopiden. (und Fortsetzung ). Bull. Soc., Imp., Moscow. Forses, 8. A.: 82a. On Some Entomostraca of .Lake Michigan and Adjacent Waters. Amer. Naturalist, Vol. XVI, pp. 537-542, and 640-649. *82b. The First Food of the Common Whitefish. Rep. U. S. Com. Fish and Fisheries for 1881, pp. 771-782. "91. On Some Lake Superior Entomostraca. Rep. U.S. Com. Fish and Fisheries, 1887, pp. 701-718. "93. A Preliminary "Report on the Aquatic Invertebrate Fauna ee the Yellowstone National Park, Wyoming, and of the Flathead — Region of Montana. Bull. U. S. Fish Com. for 1891, pp. 209-258. & Fric, A.: % "72, Die Krustenthiere Bohmens. Archiv der naturwiss. Landesdurch- ti forschg. von Bohmen., II Bd., IV Abth., pp. 203-269. N 22 MICHIGAN FISH COMMISSION—BULLETIN NO. 5. -DEGUERNE and RIcHARD.: ; ’89. Révision des Calanides d’eau douce. Mem. de la Soc. Zool.de France, Vol. II. 2 | DEGUERNE, J.: | i ho ea. Description du Centropages Grimaldi, Copépode nouveau du Golf de Finlande. Bull. Soc. Zool. de France, XI. fered HELLER, C.: ‘70. Untersuchungen tiber die Crustaceen Tyrols. ye des medic. naturw. Vereins in Innsbruck. 1 Jhrg. pp. 7-96 Hunric, OFS Ing 82. Cyclopide of Minn. with Notes on other Copepods. 10th Ann. Rep. Geol. and Nat. Hist. Sur. Minn. pp. 221-235. ’83. Heterogenetic Development in Diaptomus. Amer. Nat. Vol. X VII, pp. 381-389, 499-505. 84. OTH 09 DO - PLATE III. Fig. Epischura lacustris—first foot x 217. second foot x 153. pb sf fifth foot of female x 217. fifth foot of male x 153. abdomen of female x 113. abdomen of male x 113. OP OUR C9 DO ae! iH rt CUS ves hie de ew A" rex \ ty Oy Pry SS Se Lee , RC ey { ¢ ! ene iy bd te 24 MICHIGAN FISH COMMISSION—BULLETIN NO. = S° PLATE IV. Fig. 1. L macrurus—right antenna of male x 275. of left antenna of male x 275. PLATE V. Fig. 1. L. macrurus—first foot x 275. 2. si second foot x 275. Tinea A fifth foot of female x 275. etre. | Arar eds es fifth foot of male x 275. | Gane i second and third joints of second mmaxillipede age I 275. PLATE VI. am | Fig. 1. Cyclops ater—abdomen of male x 146. . eas | 2. “ receptaculum seminis x 113. "Me 3. 3 7 fourth foot x 1138. j 4. :. “11th, 12th, and 13th antennal segments of female x 113. , 5, ‘“ fuscus—terminal joints of female antenna x 217. 6. “ ater—terminal joints of female antenna x 217. ¢ ‘“ fuscus—terminal joint of endopodite of fourth foot x 217. 8. ‘¢ albidus—terminal joint of endopodite of fourth foot x 280. a; i terminal joint of endopodite of fourth foot | x 280 10. i se antennule x 217. Tt. *¢ fuscus—antennule, first three joints x 217. 12. ‘““ ater—outline of cephalothorax of female x 108. PLATE VII. 1 Diaptomus sicilis—fifth feet of male x 140. 2 Ashlandi—fifth feet of male x 140. 3 i minutus—fifth feet of male x 140. zt ry is fifth foot of female x 250. 5 oregonensis—fifth feet of male x 140. 6 se pallidus—fitth feet of male x 200. Jk leptopus—fifth feet of male x 138. 8. sanguineus—fifth feet of male x 138. 9 nf Birgei—fitth feet of male x 136. 10 sanguineus—terminal joints of male antenna x 136. 11 sicilis—terminal joints of male antennax 136. 12. Cyclops brevispinosus—fifth foot x 250. 13: +s modestus—fifth foot x 250. 14, “« pulchellus—fifth foot x 250. 15. ae Leuckarti—fitth foot X 250. PLATE VIII. Sketch map of Lake St. Clair and vicinity, showing collecting stations. — | PLATE IX. | Sketch map of Charlevoix and vicinity showing collecting stations. — SSSSSSSHsq <= Fae - A =e — SSS > {> yy) = = fi SE AL SS Kl | Se SSS / \ 3 = - | See Re Rae SSS SE Ee es = SSS Sa ee SSS <— == ———= > = = = S SS => és SSS = = = SNS =P LIS Ss ML Zt}. JZ ; y pb a ; wy ea oa Zp > EN i 4 : | ; Z — Ze tp tile = ‘ae I a ——_ ad ze as Wy a 1 IS Yl = i = Me iY” —=— ae 5 SS pF = gelled tO L_— 5 SZ = a= << i_————— {_— SSS ar a, “ EZ Z : A My Z y J e= Wy’, a thy Z We —= —e \ ==. = \ is pues SEES = Z SS \ S ‘ ~ = Ss = € ‘\ WOS : \ N WS SSR, y Ai mages ! l roo ‘ iy — J ZZ = EE__A Z LL a= <= eS! ZZ | LLL a : SSS PSS ‘ ZZ = Z anh EEE Ze » ——— < = SSNS = 2 ; = —— es 6 r tas oN Le“ — { o rc iY (1 71 ~ . SKETCH MAP OF | LAKE ST.CLAIR AND VICINITY Scale of Statute Miles 7H NORTH BASS 1. £3 -._f XIX es af moore BASS |. Ger BASS |, KELLEYS I. PLATE VIII. y pe 3 . et - : - Oe ae 2 OTC ea ha Ma X ‘| ee ee at — wr % oy re a' Shaw Gfht se oo. oe ; r ‘3 * q 0 = . Lalas ‘ . . . . . . a \ A \ ee C 2” & Wy = 42 i = MY Ly ) . AINA! ) ic , i N THE LIMNETIC CRUSTACEA OF GREEN LAKE. _C. DWIGHT MARSH, Professor of Biology, Ripon College. HE TRANSACTIONS OF THE WISCONSIN ACADEMY OF SCIENCES, CNEDEE, AND LETTERS, VoL. XI. : [Issued August, 1897.] tad ih ON THE LIMNETIC CRUSTACEA OF GREEN LAKE. BY C. DWIGHT MARSH, Professor of Biology in Ripon College. WITH PLATES V TO XIV. The investigations on which this paper is based were com- menced in August, 1893. At that time I constructed a vertical ‘net, which could beclosed at any depth. With this net I made twelve series of five meter hauls in a little more than twenty- four hours. My object was to determine the facts in regard to the diurnal migration of limnetic crustacea,— a migration which I was certain, at that time, took place. The material obtained in these collections was carefully counted, the results tabulated, and reduced to percentages, and a report on the subject was made at the summer meeting of the Wisconsin Academy, in June, 1894, and a brief réswmé was published in the American Naturalist in the same year. So far as difference of diurnal distribution was concerned, the experiments gave only negative results, but certain facts in regard to the general vertical distribution of the different species came out very clearly. It seemed to me probable, how- ever, that the distribution might not be the same on different days, and, in all probability, would differ greatly in the differ- ent seasons. At that time, very little had been published in regard to the occurrence of the entomostraca in different seasons. It seemed to me that if a systematic series of collec- tions could be made throughout the year, the results would be very interesting. The matter was brought to the attention of the trustees of Ripon College, who recognized its importance, and made a special appropriation to pay the necessary expenses of the investigation. ——— 180 Marsh—Limnetic Crustacea of Green Lake. The work was commenced in the latter part of September, 1894. During the fall the lake was visited twice each week, and at each visit from one to four series of collections were made. In the winter, while the lake was closed by ice, only three collections were made. From the latter part of April, 1895, until July, collections were made at intervals of about one week. In July and August no collections were made, but. in September the work was resumed, and collections were made at intervals of about one month until July, 1896. From July, 1896, to December, weekly collections were made. Thus I had a series of collections running through a little over two years, with the exception that for the months of July and August, I had only the collections of 1896. - During the time in which this work has been going on, con siderable has been published on the periodicity and distribution of the limnetic crustacea, so that some of my results are simply corroborative of the work of others, especially in regard to the seasonal distribution of the crustacea. The peculiar character of Green Lake and its fauna and flora, however, makes simply corroborative work important, and some of the results, I think, are entirely new. I wish to acknowledge the very efficient assistance of Mr. P. S. Collins, of Ripon, in the work of making the collections and observations. Sherwood Forest Hotel was the headquarters of the station work, and I am greatly indebted to the proprie- tor, Mr. Beckwith, and Mrs. Beckwith, for innumerable courte- sies. GREEN LAKE. The general character of Green Lake has been indicated in my former paper. (Marsh, ’91,b.) It is along, narrow body of water, something over seven miles in length, and with a maximum width of less than two miles. At the eastern end where it is fed by a small stream, Silver Creek, the shore is low and swampy. At the western end another small stream enters, and here also the shore is low, but most of the shore line is made of bluffs of greater or less elevation. At Lucas’s Point and Sugar Loaf are abrupt cliffs of Potsdam sandstone. There arealarge number of | Marsh—Limnetic Crustacea of Green Lake. 181 springs on the south shore, and it is popularly pale wines that most of the water is derived from this source. The water of the lake is clear, of a beautiful green color, and reaches a maximum depth of two hundred and seventeen feet. The bottom in the deep water consists of a fine, blue clay, con- taining a large amount of organic matter, in which are found worms, none of which have been determined. In the general character of its fauna, Green Lake resembles, in a striking manner, the Great Lakes. In its abysmal fauna, we find Pontoporeia Hoyt and Mysis relicta,—species which have not been found in America outside of the Great Lakes. In the intermediate depths is Limnocalanus macrurus,—a species sel- dom found except in the larger bodies of water, and in the upper layers are found the same species as in the Great Lakes with two exceptions,— C. pulchellus and D. Ashlandi. There is never any striking amount of vegetable matter in Green Lake except in the months of July and August, when ordinarily an Anabaena, which I thinkis either flosaquae or circinalis is found all over the lake, and forms little green ridges as it is washed up on the shore by the waves. But even this is not present in sufficient amount to form a scum, and never fouls the collecting net to any extent, as does the “scum” of shallower lakes. Apstein divides lakes into two groups, which he styles Chro- occaceae lakes and Dinobryon lakes. According to the general characteristics which he gives to these two groups, Green Lake should be a Dinobryon lake, and yet I have never found Dinobryon in it. It seems to me that our lakes in this part of North America can naturally be divided into the two classes of “deep” and “shallow” lakes, the faunae of the two classes being very distinct in their general character. The “shallow” lakes have, in the summer season, a large amount of the chlorophyll bearing algae; there is but little distinction between the littoral and limnetic species of Cyclops; Limocalanus macrurus is seldom present; and the abundant species of Diaptomus is oregonensis. LEpischura lacustris may be present in shallow lakes, but is not always found. In the deep water fauna of the “deep” lakes the common 182 Marsh—Limnetic Crustacea of Green Lake. species of Cyclops are brevispinosus, pulchellus and fluviatilis ; Epischura lacustris and Limnocalanus macrurus are commonly present, and Diaptomus is represented by D. sicilis and D. minu- tus: D. Ashlandi, is, so far as my observations go, confined to the Great Lakes and bodies of water in immediate connection with them. The distinction thus made in regard to the distribution of Diaptomus is not without exception by any means, and I think that 1n more northern lakes D. minutus is found more abundantly ~ in shallow lakes than it is in the region that has been more es- pecially the subject of my studies. Inasmuch as minutus is found in great abundance in Greenland and Iceland, I presume that the real cause of its greater abundance in_the deeper lakes of our latitude is not the depth of the water, but the low tem- perature which is coincident with depth. In general, we may say that depth rather than extent of sur- face controls the character of the crustacean fauna. This is strikingly shown in a comparison of Green Lake with Lake Winnebago. Lake Winnebago is situated about twenty-five miles from Green Lake, and is about twenty-eight miles long by eight to ten miles broad. Through its whole extent it is very shallow, being for the most part from ten to thirty feet in depth. Its crustacean fauna consists of those species characteristic of shal- low lakes, being very different from that of Green Lake. The same > thing is noticed in comparing the fauna of Lake Mendota, as deter- _ mined by Professor Birge, with that of Green Lake, Mendota fall- ing distinctly into the class of shallow lakes. What depth may be considered as characterizing deep lakes, it is difficult to state with certainty, and I suppose it is doubtful if an exact limit can be fixed, but I think it is about forty meters. Lake Men- dota, according to the soundings of Professor Birge, has a max- imum depth of twenty-two meters. Lake Geneva is a little over forty meters in depth, and, judging from the collections of Pro- fessor Forbes, is somewhat intermediate in the character of its fauna between the shallow and deep lakes. Lake St. Clair is apparently an exception to this classification, as, although it is shallow, it has also the fauna of the deep lakes. This is easily explained, however, if we remember, as stated in my former re- om iy! 4. One Marsh—Limnetic Crustacea of Green Lake. 183 port, (Marsh, ’95, p. 4,) that Lake St. Clair has an immediate and constant connection with the deeper lakes, and there is, doubtless, continual migration into it of the forms characteris- tic of deep water. DESCRIPTION OF THE DREDGE.— PLATES XIII, XIV. The dredge which I have used was constructed after several experiments, and has, I think, answered admirably the require- ments of my work. Inasmuch as I expected to use it entirely for vertical work, it did not seem necessary that it should be closed when descending, but that there should be some device for closing it at any desired point on its upward course. The upper frame of the dredge is a brass ring from which by three cords is suspended the bucket. The upper frame is thirty-one - centimeters in diameter. The bucket is like that described by Professor Birge. (Birge, "95, p. 428). Inasmuch as the wire gauze used in the bucket has meshes 1-100 of an inch in diameter, it does not retain the smallest organisms, but serves perfectly well as an apparatus for catching crustacea. The dredge bag is of India linen, carefully selected so as to get cloth that is fairly uniform in texture, and is suspended between the upper frame and the bucket. The dredge bag is strengthened on its upper edge by heavy cloth, into which are let the eyelets, by which it is laced to the brass rings of the frame. The cords between the frame and the bucket are continued be- low the bucket and fastened to a sounding lead weighing about six pounds. To the upper frame are attached three cords which unite in a brass ring, by which the dredge is suspended by the releasing apparatus. About half way of the length of the dredge there are attached tothe suspending cords brass rings, through which a cord runs twice in such a way that when it is drawn tight it acts like a puckering string and closes the dredge. This cord is attached to the dredge rope, which, after being fastened to the releasing apparatus, hangs loosely ovcr the edge of the dredge. The releasing apparatus consists of a brass frame (see PI. 184 Marsh—Limnetic Crustacea of Green Lake. XIII.) fifteen centimeters long, by five centimeters broad. The frame is strengthened by three transverse braces. The frame and braces are made of strips cut from sheet brass, one milli- meter thick and two centimeters wide. , Through the horizontal pieces of the apparatus are drilled two holes large enough so that the heavy brass wire D E will slide easily up anddown. To the middle of this wire at E is attached an upright piece which passes through the lower part of the frame B, and strikes against the brace C. The wire is held in place by a rubber band passing around the plate B. The dredge is hung from this central pin at E, and cannot be detached except as the wire D E is lowered so as to throw the ring off the pin. ‘The releasing apparatus is fastened to the dredge rope by copper wire passed through small holes drilled in the upper and lower plates. The messenger is a brass cylinder five centi- meters long and four centimeters in diameter. The work of dredging is done from a row boat which is fitted with a sail. The mast is unshipped, and in the mast hole is in- serted an upright about six feet long, to which is attached a cross piece extending over the side of the boat. From this cross piece the dredge is suspended by a pulley block, and upon the cross piece is a hook from which the messenger is suspended. The dredge is lowered vertically, and after being raised to the required point, is “set off” by the messenger. When the mes- senger strikes the releasing apparatus the top of the dredge falls over, and it remains suspended by the middle. At the same time the weight of the lead causes the cord around the middle of the dredge to tighten, so that there is a double safe- guard against the entrance of any other organisms — the in- verted top and the stricture of the suspending cord. There is one sour ce of inaccuracy in this dredge, and that is the loss of material, when it is released, between the top and the cord passing around the center. My hauls, however, were made through five meter distances, and I do not think that in this distance, the loss would have much effect on the results, and, of course, for comparative work it need not be considered at all. Marsh—Limnetic Crustacea of Green Lake. 185 For winter work, the apparatus is hung from a tripod placed over a hole in the ice. (Plate XIV.) The tube at the bottom of the bucket was made of a size to fit in the top of an eight drachm homeopathic bottle, and in or- der to preserve material, I simply washed it with strong alcohol immediately from the bucket into the bottle. A buoy was anchored in from forty to forty-five meters of water, and all collections were made from that point. In suc- cessive years the buoy was located in very nearly the same place, and when collections were made through the ice, it was intended that they should be taken at nearly the location of the buoy. Collections were made in all kinds of weather, but more were made in comparatively pleasant weather, as naturally one would prefer to visit the lake under such conditions. The record of observations was kept in a book arranged for the purpose. A sample page of this book appears on the next page. | The temperatures were taken by a Miller-Casella deep-sea, maximum and minimum thermometer, which was loaned to me by the United States Fish Commission for the purpose. As those who have used this form of thermometer know, it is very slow in its action, it being necessary to allow at least twenty min- utes for each observation. This made it impossible for me to get a record of temperatures at intermediate depths, although such a record is very important in determining the laws gov- erning the vertical distribution. The temperature curves of the two years, 1895 and 1896, are shown in plates V and VI, with the exception that no observations were made in July and August, 1895. It will be noticed that the maximum range of bottom temperature observed was from 35 to 45 degrees, thus indicating great uniformity of conditions. of temperature at the bottom. 186 Marsh—Limnetic Crustacea of Green Lake. SERIAL COLLECTION. . No. 13.96. at permanent station................ eA oy SEN) UN ie Si depth 43.5 mrsc5 eee water, .‘.... small waves; ..... NAVINI eh ca awa SESS esas Nie Shey Woe), auc clears chee temperature, air ...83;... temperature, surface, .. 75; ... temperature, bottom... 43;... - Observed Diaptomi, D, minutus, C. fluviatilis egg-bearing. Much fine sand in collec- tion: is explained perhaps by the high wind earlier in the day. Names. 0-5 | 5-10 | 10-15) 15-20)20-25 |25-30/30-35 | 35-40 | 40-45 | 45-50|50-55|55-60| Total Diaptomus sicilis...| 760)1,192; 272} 40} 140} 14) 11) 75 yO seemed iivsan li oT ct se Ashlandiit22e |i. a $s AMID GUSH oe eee Se ie Seiad Tia ST yah cas a ee “ oregonensis}....|...-.|.. Epischura lacustris.| 16 BY AO erect alec. Let eeweles oileecers ener wiGrctevel i siaecalell © Slee: iy eee eee eer 30 Limnocalanus mac- TUATUS a.) aac cllkasoue 1 4 8 1 A leee! (2) PMP ey ial eres e || 29 Cyclops brevispino- SUS Se Nee ates ccia/coee Set EVULES OPETES (5 | wins clttcc'e sil voce veil eis cee Tuie'ceisd ciate] oreie averfleisieralel| isis ctw esclae ef berate eer SAV MUOUCK ANDI: A501 25 'a] Ca fe A MERLOLOLS pices lace olce sows See af iwniale Chek cate *~ fluviatilis, ..| 72) 72] 32 2 Cesar fepet a | a ia eda Near Fn ote ee 182 w ac serrulatus...|... Cyclops larve....... 160 8 riceyet 6 ch) aia Als sceis\ Ae betes elena 180 Leptodora hyalina. 2 WR aa Ts PARANA ae Been enol kore easel tee Te openS Daphnia kahlberg- LCTISES os el cue 12} 16) 40 ie.2) (ee) Pontoporeia Hoyi..|....].....].... INotholea! 2240 ac5 oe Nos].. Mysis relicta.... ..<|.cschiceus|ecess a oh PROERIN raca ee In "ie NED CWorataim sss cakes | td (2) E =r B 9 or oO bo oo (=r) ; ci ; 6 5 ; : ; 5 F 5 a ‘ : Se a ea a a SS ee es ; , i a ; 7 5 - 7 i z 5 : ; . . . . . . i 3 7 ' . rj : = . = Varsh—Limnetic Crustacea of Green Lake. 187 The surface temperature varied from the freezing point of water in winter to eighty degrees in August, 1896. In general the rise of surface temperature in the spring, and the fall in autumn, were both uniform and rapid, but there were some ex- ceptions. Very noticeable is the jog in the curve in May, 1895. In this month there was a period of unusually warm weather, followed by severe frosts. There was a curious rise in the bottom temperature in the fall of both 1894 and 1895. On November 11, 1894, I found the bottom temperature 45, while the highest point reached previous to that time was 424. On October 24, and.November 3, 1894, I found the bottom temperature 44, while the highest point reached previous to that time was 43. On November 11, 1895, the bottom temper- - ature was 45, while the highest previously recorded was 423. My first impression on seeing these temperatures was that there must have been a mistake in the observation. I felt the more certain of this probability in one case, as the observation had been made by my assistant without my direct supervision. But a repetition of the work showed that there was no mis- take. | | A similar rise in bottom temperature in November has been noticed in Lake Cochituate (Whipple, ’95, p. 205, and Fitzgerald, ’95, p. 74), and these authors have also noticed a fall in bottom temperature in the spring. These apparent ab- normalities in temperature have been explained by the above mentioned authors on the supposition that as the top and bot- tom temperatures approached each other, the water, being of nearly equal density from top to’ bottom, would be in a state of unstable equilibrium, and currents would be set in motion, which would effect the whole depth, especially under the influence of high winds. Whipple has shown (’95, p. 208), that under some circumstances an overturning and mingling of the whole mass of water in a lake may take place with almost incredible sud- denness. Although no attempt was made to keep a systematic record of other organisms than crustacea, some notes were kept of the appearance of other animals and of plants. 188 Marsh—Limnetic Crustacea of Green Lake. Of plants, the only one besides diatoms, which occurred in any abundance was the Anabaena already mentioned. In 1896 this appeared in the latter part of June, and continued well through August. In other years, I have found it present only during a very short time. I have notes also of ared alga that: was found in considerable abundance about the middle of August. In oneof the March collections there was also an un- determined green alga. Rotifera were of course present in large numbers, but no at- tempt was made to keep any record of them. Notholca longi-. spina was found throughout the year, sometimes in great abun- dance. Ceratium occurred quite constantly in the collections from June to the latter part of October, and in 1896, until the middle of November. From May throngh the year, Diptera are occasionally found in the collections. This is what one would expect, for the larvae are found in the bottom fauna. METHOD OF COUNTING. The method used in counting was somewhat different from that used by other authors, and a method that perhaps could not be used so successfully in collections containing a large amount of vegetable material. The alcohol in the bottles was largely replaced by glycerine in order to have the material in a. medium that would not evaporate rapidly. I had prepared for me a glass plate sixteen centimeters in diameter, ruled with con- centric circles a centimeter apart. The circles were divided by diameters. into eight segments. The plate was mounted on a tripod such as is used in leveling gelatine plates in bacterio- logical work, and carefully leveled. The collection was then poured as nearly as possible upon the exact center of the plate. Ordinarily it would spread with great uniformity upon the plate. The fractional part of the whole counted depended upon the numbers of the species under consideration. Commonly I counted only one-eighth of the Diaptomi. Of the species present. in smaller numbers, I would ordinarily count all on the plate. In any case all parts of the plate were examined in order to de- Marsh—Limnetic Crustacea of Green Lake. 189 tect the presence of any unusual form. This work was done with the aid of a dissecting lens such as is furnished with a Reichert dissecting microscope. This lens answered every pur- pose so far as determining the species of the crustacea, except that I could not distinguish with certainty D. minutus from D. sicilis. As the object of the counting was mainly to determine distribution, the fact that I did not distinguish between these species was of little importance, as their habits are the same. In every case, however, a test of the collection was carefully ex- amined under the compound microscope, and in this way a fairly accurate idea was obtained of the seasonal distribution of these species, and notes were made also in regard to the occurrence of other smaller organisms. No attempt, however, was made to keep any record of diatoms. The accuracy of this method of counting was carefully tested, and the amount of error was found very small,—so small that I do not think the general results would be appreciably affected. As stated before, it is very doubtful if the method could be applied so successfully to plankton rich lakes. These results were afterwards reduced to percentages in order to show the relative abundance in vertical distribution. In the following table I have tabulated the conditions under which the various collections were made. The table is, in the main, self-explanatory. To indicate the condition of the surface I have used four terms, “smooth, ripples, waves, and rough.” In the tables given for the various species the “total” column indicates the actual number obtained in my dredge. These numbers might easily be reduced to give the actual number per square meter by multiplying by the coefficient of the dredge, but my object was simply to get comparative results, and, as indicated later in this paper, I myself have only limited confi- dence in the value of plankton determinations. In the columns following “total” are given the percentages found for every five meters of depth. 190 Marsh—Limnetic Crustacea of Green Lake. | TEMP. No. Date. Time, Thy eae. Water. Sky. HI B/S aim} 1.94\Sept. 27 6230-7304) pea sO dase de S. W.|Waves ...... Clear 4.94/Oct. 10:45-11:45 a. m.|57 |60 (48 |S. W./Ripples..... Clear. 5.9410ct. 6 2:30-3:30 p.m.|59 {59 |48 |S. W.|Waves...... Clear 6.94/Oct. 6 4:50-5:45 p.m.|... Moab SBMS ite Waves ...... Clear 7.9410ct. 6....{10-11 DVIS dea lvcare See see Waves...... Clouds 8.94/Oct. 9....]6-7 Pi TR es CAM ALL Een 2 eee Waves ...... Clear 10.94/Oct. 10....|6-7 a.m.|45 [56 S. W.|/Rough ...... Clouds 11.94/Oct. 10..../9-10 Fe Mees a5] ALS POG Lee N. W./Rough ...-.. Clouds. 12.94/Oct. 16....|6-7 De Se een S. W.|Waves...... lear 13.94;Oct. 16 10:30-11:30 p. m.|54 |53 |48 |S. W.!Waves...... Clear 14.94/Oct. 17 6-7 ava) (49 53d) es W.|Waves ...... Clear. 15.9410ct. 17 8:45-9:30 a.m.|51 BUN ek W.|Waves...... Clear. 16.94|Oct. 20 11:15-12 a.m.|57 {53 }48 |S. E./Ripples..... Clouds, fog. 17.941Oct. 20 2:15-3:15 p.m.|64 |54 |....)S. E./Ripples..... Clear. 18.94/Oct. 20 4:40-5:20 p.m.|58 |..../....|S: E.|Ripples..... Clear 20.94/Oct. 24....|10-11 p.m./48 |54 |44 |S. ....)/Waves...... Clouds 21.94/Oct. 25 6-6 :50 a. m.|48 Se cenliee ees ell WEDVOSH Ogi, Clouds 22.94/0ct. 25 8:45-9:30 a.m.|....|.... See. WWW ROUe hile, ny Clouds 24.94/Nov. 3 2:45-3:30 p.m.|45 |52 [44 |S. ....|Waves...... Clouds 25.94INov. 3 4:30-5:20 p. m./45 Bil Seis DS oi N HE Ric ond esl ate pMlah ae Clouds: 26.941Nov. 8 Byes OS st aioe eooln Aneel nape ode .| S. ....|Ripples..... Clear 27 .94| Nov 10-11 p.m.|35 |49 |....|/.S. ....|/Waves ...... Clouds Q9SAIN Oye 2H ee Micinbic s.ccdevoteiae weeje oakle 38 (39 |43 W.|Ripples..... Clear 1.95|Feb. 14..../11:30-12:30 m.|29 |33 /88 |N. W.JIce.......... Clear. 2.95|Mar. 9....]11:30-12:30 m.|454%4/386 (87%|S. W./Ice........ ..(Cloudy, and rain.. 3.95|Mar. 27....|10:45-12 m.|51 |3614,37 Waitice ni sa ae Clear. 4.95|Apr. 27....|1:15-2:30 p.m.|58 |42 |40%|N. E.|/Waves...... Clear. 5.95|May 38....|/4:30-5:15 p. m.|68%/47 |40%|S. W./Change..... Cloudy 6.95|May 3....|7:20-8 Di MBS) Paola e's E.|Waves...... Clear. 7.95|May 9..../4:30-5.30 p. m./80% Bf 40%|S. W.!|Rough ...... lear 8.95|May 18....|1:25-2:05 p. m.{81 41 |N. E.|Waves...... Clouds 9.95|May 24..../4:30-5:30 p.m.|74 = 4144|S. W.|Rough ...... lear. 10.95|June 1....|10:50-11:35 a. m.|81 |68 |414%/S. W.|Rough...... Clear EOS Puarie) Gist eleeiyey see. Be Sasi 70 |65 |42 |S. E.|/Waves...... Clear 12.95|\June 15....|/4:30-5:30 p.m.|78 |68 {42 E.| Waves ...... Clear. 13.95|June 22....|12:10-1:15 p. m.|90%|72 |421%4|N. W.|Waves...... Clear. 14.95| June 28....|3:30-4:30 p.m./75 42 |INW-NE|Waves...... Clear. 15.95|Sept. 21....|2-3 p. m.|/8444|714%4!42%| S. W.|Rough ......|Clear. 16 95/Oct. 2..../4:45-5:45 p.m.|70 |60 |424%\s w-s B Ripples .. ees, Clear. 17.95/Oct. 5....|4-5 p.m.|70 |61 |424%;S. W.!Smooth..... lear. 18.95|/Oct. 24 10-11 a.m.|/40 |50 (42%4)}S. W.|Rough ...... Clear. 19.95|Nov. 11 1:30-2:30 p.m./48 |46 |45 |S. W.!|Waves Clear. 20.95|Dec. 5 12 :15-1 m.|22 )42 |43 |S. W.|Waves...... Gray. 1.96|Jan. 28 1-2 p.m.|32 (34 135 |S. W.|Ice.......... Cloudy 2.96|Feb. 22 12:30-1:30 p. m./40 |34441/25%| S. W.|\Ice.......... Clear. 3.96|Mar. 21 11:45-12:30 m./45 |86 |86 |S. W.|Ice.......... Overcast. 5.96|May 4 3:25-4:10 p.m.|86 {52 |41 |N. W./Smooth..... Clear. 6.96;May 18 3:45-4:30 p.m.|74 (55 (42 |N. W.|Waves ..... Clouds in west. 7.96|June 1 3215-4 .m.|73 |60 {43 E.|Waves...... Clear. 8.96|June 15 3 40-4 :20 .m.|&8 |69 (48% E.|Waves...... Clear. 9.96|June 29..../12:05-12:40 m.)101 |74 |48 |N.....|Smooth..... Clear 10.96\July 9....|11:45-12:30a.m./78 |75 |48 |N. E.!Waves...... Clouds 11.96) July 20....|/10:20-11:15 a. m.|78 |74 |43%|S. W.|Rough...... Clouds 12.96|\July 27....|/3:30-4:15 p.m./88%|75 |48 |S. W.|Waves...... Clouds. 13.96|Aug. 3..../6-6:40 p.m.{8 |75 |48 |S. W.|Waves...... Clear. 14.96)Aug. 10....|3:35-4:10 p.m.|..../80 |48%|S. W.|Waves...... lear 15.96)Aug. 17....|12-12 :45 m.|72 |76%|44 | N. W.|Waves...... Clear 16.96)Aug. 24....|3:25-4:05 p.m.|76 |74 W.|Waves...... Clear 17.96|Aug. 31....|9:50-10:35 a.m.|68 |70 '44 |N. W.|Waves Clouds 18.96 Sept. 7....|9:25-10:15 a.m.|78%/66 |44 |S. W.|Rough ...... Clear 19. 96! Sept. 15....13.20-4:05 p.m.|62%|65 |[444%4)N. E.|Waves...... lear. 20.96|Sept. 21..../2:45-3:30 p.m.|70 44 |N. E.|Waves...... Clouds 21.96|Sept. 28..../2.55-3.40 p.m.|70 J61 |43% E.|Ripples..... Clear 22.96,0ct. 6..../11-11:35 a.m.|&9 [58 |44 |N. W.!Waves...... Clouds 23.96/Oct. 15..../12:45-1:20 p.m.|67 |56 |484%)N.....|Waves...... Clouds 24.96'Oct. 24....)11:30-12:15 m.150 |51%/48%)N. W.|Waves...... Clear 25.96|Nov. 14..../8.50-4:40 p.m./49 /45 |48 |S. W.,Waves...... Clear. 26.96|Nov. 14....|7:20-8:45 p.m.}..../45 |....]S. W.|Waves...... Clear, moonlight. 27.96|Dec. 3....)11:15-12 a.m.|41 [4134/8944] S. ....|Waves...... Hazy. we Tor ee eS | Marsh—Limnetic Crustacea of Green Lake. 191 DIAPTOMUS. Per cent. No. |Total of Coll.| No. 0-5 | 5-10 | 10-15 | 15-20 | 20-25 | 25-30 | 30-35 | 35-40 | 40- 1.94..| 3,912) 58.64) 11.63) 12.48) 7.16) 1.23) 5.11) 1.43) 1.02} 1.23 4.94..| 5,630! 60.25} 24.58} 7.18} 2.34) 3.81 .85 .78 .78 43. 5.94. .| 4,171) 72.50) 14.67), 3.93) 4.22 abe: oe .86 ae. .26 6.94..| 4,382} 73.80} 16.00) 4. 3.40 ite ial) 240 SOONG ae 7.94. .| 2,023) 46.27| 20.56) 11.86} 12.46) 2.37) 1.98] 1.19 134} 2.97 8.94..| 4,585} 68.57) 20.54) 4.62) 2.62 .26 591). 1.92 .87 .70 10.94..| 4,040} 28.61) 26.93) 31.78] 7.82) 2.77 74 .79 RO vgs 11.94..| 3,991) 54.92/ 14.88! 17.24) 3.66] 1.05) 7.02 45 .50 .28 12.94. .| 6,439] 36.77| 19.32] 17.52} 6.21] 13.36) 5.60 ay .25 .20 13.94. :\ 4,611) 57.73) 13.54) 16.39) 5.12). 5.29) 1.34 5 24 .19 14.94..| 4,347! 45.73] 19.05) 23.92) 7.72) 1.84) 1.14 yA 25 .18 15.94..| 3,466) 46.39} 27.81! 14.19} 9.81 BSS A Weak 8 .38 .69 .20 16.94..| 1,763) 59.44) 17.92) 13.16) 4.36) 3.18 .28 BR ee .19 47.942.) 1,542) 71.92). 17.38) 4.60). 3.76 .58 .39 .52 .26 .39 18.94..| 1,386} 80.81} 4.97) 10.39) 1.44 .58 {BEN TOL .O1 43 BE LSA SURI OE NG TE Se IP ROE Os ner PC A 9 DAN He 20.94..| 2,197) 59.17) 18.02] 15.66) 1.86) 2.82) 1.91 04 .36 84 2h 94) 1 1,917) 35.89) 27.335) 25.45). 4.23) 2.87): 2.39) dtd .58 pl 22 -94..| 3,823] 60.27) 24.48] 9.52) 3.19 .71| 1.59 SBR Sas .05 ma 94 LOZ) (6.12) 12.99) 1034), 6:23) L117) 2213 .56 .61 125 25.94..} 1,695} 63.30) 28. Ze en Ae OO .70 .18 .10 10 26.94.. Bea feo) La oe ok Sh 4th P.S6) B87 136 .90 .68 27.94..| 6,447] 28.29; 21.98; 25.56! 13.57} 9.06 .85 .39 .16 a 29.94. .| 1,192) 40.60) 10.73] 11.41) 6.03} 7.06) 10.73) 4.03} 6.72) 2.69 Peay tora 26.80) teO0) 22.138) ST. ae 2.04 5.58) 0.57) 1368 Glee 2.95..) 1,947) 28.35] 9.86} 2.67] 18.02) 27.94) 4.11) 2.92) 4.71) 1.48 Suds.) Ay bee) OSo.at) 4.67) (4521 2.77) 4.82) 3.50) SLIT) 3.87) 2247 4.95.. 676) 1490) AG 15) y22 49) 13-02) 8/88) 7.69) 19.42) Brea) ioe 5. yO.” 686) 35.27} 9.91) 14.58} 6.99} 5.25) 11.67) 9.04) 5.25) 2.04 6.95.. 694! 29.39! 18.44) 23.05} 8.07) 4.61} 6.48 ihe SIGi 05 7.95.. 286 .69} 15.39} 14.69} 5.59/ 15.39) 24.48] 16.08} 3.50) 4.19 8.95.. Wary U.aor 10,001) 28-1) LOL Ot Le TS) 16.27) 7.46) EE byron 9.95.. 576| 44.44) 22.22) 4.16) 10.41) 6.08} 4.51| 2.60) 2.79) 2.79 10.95. .} 1,845} 66.88) 22.98) 6.08 .16} 1.30 Best) ihe bes .65 127 ais 2a LS a Ae a a Or | ER | MR DA LH Mt 12.95. .| 2,950) 40.68) 29.29) 14.10] 10.31) 1.62) 3.12 AT 14 Wry 13.95. .| 2,612} 21.44! 18.07) 19.91] 14.70} 7.66) 5.51; 4.90) 4.59) 3.22 14.95. .| 3,039) 54.72) 22.51} 5.79) 7.63) 4.21} 1.71 G6). 1245) .82 15.95..| 2,605) 37.77) 24.57) 12.59] 6.45) 9.52) 1.84) 2.46) 4.15 .65 16.95. .| 1,748) 34.32) 35.69) 18.31) 4.12) 1.83} 1.38} 1.14) 2.75 .46 Ot 9p. 1, 1, 813) 10.59)43..a5) 35:54| 4.85) 4.861) 1.27 .88 NF (RS Ne 48.95. .1 1,667) 51.35) 10.32) 11.52) 18.23) 7.32 Lites .36 AA K 3) meme 19.95.. G47)42 O41 73. Ty 24) OL 02) 17.93) 8.65) STL) DO oe. 20.95.. BAO) od. Goh i sOo) oaet O. 2a) GO. 9a1 10.7%), 122311) BBB) oa 1.96.. 485-0052. 19.79} 4.95} 3.30) 36.28] 13.20) 17.53) 1.65) 3.30 2.96..) 1,324) 25.98) 11.48) 10.88] 12.08) 23.56) 7.25) 1.81) 3.33) 3.63 3.96.. 892) 35.43] 23.32) 11.88) 9.42) 6.28) 5.38! 5.38] 2.24 .67 §.96..| 1,712) 74.77) 5.61). 5.84) 2.57 .82| 2.10} 4.91; 1.87} 1.52 6.96.. 297) ao.00| 1007) Sa.67 5339) 2.70), 4.04) 4:71) 3:37) 1.68 7.96..| 2,712) 36.87) 50.44) 9.44) 1.62 .89 .30 .29 11 04 8.96..| 3,044) 27.59’ 47,83) 138.14) 3.68) 3.71 .65) 1.70 .78 92. 192 Marsh—Limnetic Crustacea of Green Lake. DIAPTOMUS — continued. Per cent. No. |Total. of Coll.| No. . . 0-5 | 5-10 | 10-15} 15-20 | 20-25 | 25-30 | 30-35 | 35-40 | 40- 9.96..! 2,392) 56.52) 25.09} 10.70; 5.02 75 50 20 12) Be 10.96. .| 2,354} 39.50) 33.30} 8.84) 6.12 25 69| 1.44) 4.76) 5.10 TL 96.1 2, 793i 36.17) 24.68) 28.0 2.72 46) 1.25 .68] 4.80) 1.22 12.96. .| 3,612) 47.84} 37.65) 9.74) 2.99 .30 ip iy 6 AT .39 13.96. .| 2,508) 30.30) 47.53} 10.84) 1.60) 5.58 .56 .44| 2,99 16 3, 803} 64.16} 19.99} 6.42; 3.10)...... 2.84) 2.52 26 71 16.96. .{ 4,785} 62.90) 9.01) 18.06} 1.25) 2.01) 2.67; 1.33) 2.17 60 17.96. .| 4,933) 41.60} 28.81) 19.62) 1.87) 2.59 Da .89} 2.27) 1.78 18.96. .} 5,646) 70.86 .42} 15.02} 4.85 49 .98! 4.83 TO degy 19.96..) 4,766} 46.37) 33.02) 6.73) 3.35) 2.35) 3.02} 3.86; 1.09 21 20.96. .| 5,248} 59.18} 21.80} 6.25) 1.22! 2.04) 3.43) 4.08 69 91 21.96..| 3,772| 54.72) 26.73) 14.21) 1.06 95} 1.01 .64 13 50 22.96..| 4,229} 45.40} 19.11) 23.22) 9.27) 2.46 Bia col 07 flay; {2 23.96..| 4,736) 78.21; 7.43) 8.96) 4.39 46 as Je is 04 24.96..| 1,527} 54.49) 16.76) 23.58) 4.19 26 20 13 26 13 95.96..| 746] 18.23| 7.51] 6.43] 15.55! 16.09] 23.59 7.50| 3.76] 1.34 26 .96.. 490]in 0-20| meter'is. 27.96..| 7621 42. | 7.35) 9.981 6.30] 4.20] 5.77] 6.99] 15.75} 2.36 A glance at Pl. VII will show that Diaptomus has a strongly marked minimum of occurrence in December and in January. There is an increase in February and March, but in both 1895 and 1896, the number in May was very small. Diaptomus ap- pears to reach its maximum in the latter part of September and October. In the fall months, the collections consist mostly of mature forms. In the winter months most of them are immature. From the latter part of March to the latter part of May, nearly all are mature, and the females egg-bearing. In June there is a great preponderance of larve. Apstein (’96, 179 and following) states that the maximum period of D. graciloides differs in different German lakes. The time of the maximum occurrence of Green Lake Diaptomi as re- corded above, does not agree with any of his observations. Birge (Birge 95 p. 448) states that the maximum time of Diapto- musin Lake Mendotaisin July. Inasmuch as Diaptomus is very little affected by differences of temperature, as will be shown later, I think these differences in maximum periods are prob- i er = Marsh—Limnetic Crustacea of Green Lake. 193 ably caused by some differences in the development of food sup- ply. There are only two species of Diaptomus found in Green Lake, — D. minutus and D. sicilis. In the counting no distinction was made in regard to these species, but a slide was prepared from each collection and examined under the compound micro- scope and thus a rough idea obtained of the relative abundance of the two forms. During Sept. and Oct. D. minutus was much more abundant. In Sept. very few of D. sicilis were found. Dur- ing October and November the relative number of D. sicilis in- creases, and in the winter months the collections were almost entirely of D. sicilis. In 1894 I first found D. sicidis in the collection of Sept. 28. In 1895 it first appeared Oct. 5, and 1896 on Oct. 6. Although _I did not find this species in the summer months while I was making my serial collections, I do not think that it was probably entirely absent from the lake; for in 1890 and 1891 I found it in summer collections, although I did not find it in 1892. (Marsh, ’93 p. 198.) I find, on looking over my notes of 1890 and 1891 that it was not numerous in those years, and I presume that it occurs in the summer months, but only in very small numbers. A reexamination of my notes on the Michigan copepods shows that the same thing holds true there. In the collections made by Professor Reighard in April, in Lake Michigan, D. sicilis was always present, while in the summer collections in the Great Lakes and Lake Michigan, D. minutus was the more com- mon form, as I have already noted in my paper on Michigan copepods, and J. sicilis occurs rather infrequently. In April and May D. minutus is entirely lacking in Green Lake, but appears again in June. Inasmuch as it is claimed by some that some copepods show a seasonal dimorphism, one might raise the question whether we did not here have a case of that kind. I do not think that this is so, although I have not now material to fortify my be- lief. : The Diaptomi are found at all depths, but in the deeper strata only in small numbers. There were very few hauls in which I 13 194 Marsh—Limnetic Crustacea of Green Lake. did not find some representatives of this genus in every five meter stratum, and yet from sixty to seventy-five per cent. were commonly in the upper ten meters. In order to find out whether there was any difference in the vertical distribution in summer and in winter I took the averages in the upper three levels of collections 7.96 to 17.96 inclusive, and 24.94 to 3.95 inclusive. I took these years because in 1894-5 I made a large number of collections in cold weather, and in 1896 I made the largest number of collections in warm weather. The following table indicates the results: 0-5 5-10 10-15 Summer, T9017 0G6. 2 ojo. sic eate : 49.31 24.49 12.26 Winter, 24.94-3.95.............00.- 50.02 13.50 10.12 It appears from these averages that the seasons make no difference in the vertical distribution of Diaptomus, but that it is uniform throughout the year. Apstein comes to the same conclusion. (’96, p. 180.) The day and night collections of October, 1894, compared as follows: 0-5 5-10 SES ail i CRA CAE AR RUS) Ra ORO OES eC tl NAR! 59.44 18.42 © ee PR ME LIN aT RMA MORNE Cres ali AN 53.70 18.40 Here is no evidence of diurnal migration. I think, then, that I am safe in saying that the vertical dis. tribution of Diaptomus varies but little from one end of the year to the other and is not appreciably affected by changes in the amount of light. | Birge finds the same thing to be true of D. oregonensis. (Birge, ’95, 450.) et __emmmmmm m a maaaa Marsh—Limnetic Crustacea of Green Lake. 195 No. |Total.|__ of Coll-| No. EPISCHURA LACUSTRIS, Per cent. 0-5 | 5-10 | 10-15 | 15-20 | 20-25 | 25-30 | 30-35 | 35-40} 40- EN Maa LE saaly SOcGol \ Do Behe aivaiay be’ gteesa ihe’ akeratalfteayain“s 9 fhoke’ areht oi lovaie elas 4.94..| 121) 59.50) 33.06) 6.61 Net a (as a (ENR ao ONE A NS UY 5.94..| 100} 56 Pe POTS lr Be Mi ieaevadte sake eel on eianenatedvets Sek ole gees 6.94..| 180) 87 8.30} 4.44)...... BA toes items cn sian + Reogeaneee 7.94. 149), 34:90) 32.20) 18.79) 10.714) 2. 69h. cabs dee tatiees Jee 67 8.94..| 390) 41.54) 33.82) 16.41) 5.13 ol 26] 1.56 51} = .26 10.94. 220} 50.90) 21.82] 23.63) 2.72 Detaled. (gia lhe rsimie: nla biae aja a eifheig a arope 11.94..| 191} 54.45) 15.71) 25.13) 2.09)...... A | | Re Bab sneein 12.94...) 104) 19.23} 7.69) 9.61) 38.46) 11.54) 11.54) .96 BG) esos 43.94..| . 141) 28.37) 12.35) 45.39) 8.51) 2.84) 3.54)... 0.702... [sees ae 14.94..} 126) 38.09} 19.05) 22.22) 9.52) 9.52) .79)...... ay | eae 15.94..| 214) 56.08) 18.69) 20.56)...... yt | ee .93) .47 47 16.94.. Baas ||) LATO” Soap Oa lah, wesc a 5 ean pos 40 17.94.. 50| 64. | 28. 2 ARS ie PE ee FN pie de ee aay ed wig 2M I os be dA: PRRs My 9 GE We ly | Bs (NPR ae 2 20.94... 95) 23.16} 25.26] 47.37)...... BI a 0 5 ee Am en ey 21.94.. 65} 49.23) 24.61) 21.54) 3.08]...... Beales ispvale|incs seve avenue 22.94.. BZA WM Sy UO La) AS 5 Riad ae BPs fC MAE “A as [Oe 24.94.. LLCS | ER a are DNs soles calslaib wcaleras eraitie Silas elisdadaees yea ee 25.94... 22| 31.82] 45.45]...... DOF OO) Bah ws abe voles iearclone 26.94..| 118] 74.57' 14.41) 4.24) 5.93)......]...... BO Oe as.silela eke ~27.94..| 330) 53.33] 5.45) 31.52} 8.49 EP SAN ies ill i aaier eet miata 29.94.. 1D Se ge el SP ae a 11) US eee asc Ge ee EAS, RGN Ee 1395: chen seed AO RIM 3 So dele ae blah 5.4 dina a lvmratavee caper a jak Padre tala 2.95..| 395) 50.63) 8.10) 8.10) 16.46) 14.17) 2.04)...... Ola 2 5 Sere 3.95.. Zep Obie OU iais skis chugs sa pt pier.) sella ahd ay pb audio ale ll shacbiaceg 5 3 ts 3, ee Ba cyelere dicifiencnsi ceaye [eas een ae wile ae pm iajanala gio uae aysis Uaie aera siflaisie acd | alateahe fe piacere es ER PT Po fe le Ey ae ed en re a eee Pre iy 1) eee ice tate Oe aieiliet iain « Ney aisre pall Sierotena Ei oats "eal ing nse eiita'strate slau ¢ elt heaebaeys eRe sta nie doers |lovarayav rita e anat el al arya'ch's Lile/ace Bh ate Nayar 3iar abn bale are we her atal ayaa tesa aces Ree Mar Jie tis i ater Mee Hoteles Shahi aless Potaia iuharailiay Sit ig SU c's + aceite etx a hadaetetals reamed s etary epueneral ie states wa frat arnt re Sia ot Pala a ovaj Tes Oued sella bad io! iaigslat ee flares Senate 10.95... 93} 98.72)...... 19 2) PCAN ee eed eRe IP Uae age CO 11.95.. 96] 33.33) 58.33)...... NEE ate ae tail ocgat tata ua hm nic 8 Nha ge a hee orks 12.95... BE POE PSO mul rae oles vincstefidn Ne ac baree dual we mcuelwanen 13.95... Bae OO et, Oe a LANL AS elas weet: soe ate uld sole cele. Eee ain Poel) 242 Goma A ORh yy AOE oa cls elastase wed «baie oop alles dees 15.95... 24) 50 12.50) 25. ART) Ak BPG Selamat é SeiGpo vss: 16.95... 65} 73.84] 18.46) 4.62)...... DADE goo lk hy a rE: Oe 47.95... SU) See OE Bol ee Gah uae oN Ua bel accel de ceils calace 18.95..| 100/ 48 20. oem Me CP SP tech i LPT MA SP Sg 8 ee 19 95.. 4! 50 Rasta e ersyensiae tocar tara ail ie slclis wf aap home iae aialelef ow dds Pa A ay ae a2 hs ss dacs Weaicletas Poe ee etd Ais Palins eee af whl cone tae olnye bameaieiep otaeid's 1.96. 7:5 Oe a fae PS Re S| ME | 22.87} 39.46]...... 2.96. 96] 58.33) 33.33)...... Gea eateries calomel aoe oe ete elie Wace eee tees Sei tis/s) Ceara hb uceeae BRS 11.96.. ay a Oe 5G Shy MG OOM Oa bah Aa icine 2 Ba ce 12.96.. BID SOO a! DAs Ga Gc bep ho le uae ah a POO yc teite 13.96 84) 14.99) 19.05). 47562) 9.52) O58 lo 14.96 37) HOC PA G2501 BT BOW oe ee sien ollie chcece ills ectie eal eee 15.96 5 aly 0 JN Rh eH IC AD Sl NS AAA Mabe 8 20 20 40 16.96 OSE Nr 3.70} 81.48} 11.12 93) DTT ee ee 17.96 Hele cae SO) aes) Weg aall) MAN OR eceneed [elena be S79) aa nN 18.96 Fete TAS 24 Ee 32.08) Go.02| 6.85) AST. Ghat ae ee 19.96 SO sre aT 9.30) 10.46) 13-96) 116 ae 20.96 92) 60.87|. 8.70) 6.52! 4.35! 13.04! . 3.26] 2.17) Losin ‘21.96 94) 34.04; 42.55; 8.51) 8.51} 1.07) 4.26) 1.06 22.96 78) 10:26|'°30.77) 35.89] 12.82): 3:85! 2.57). | 2°56) aes 23.96 223) 46.19] 17.94) 17.94] 10.76} 5.38 89 AB i 45 24.96 fj Ee ST NS 743y7.45 fas faim <8 ae Rit | MAT DTT osc Ae 25 907. 6b! (59.02) 26:23) 'G.56) | 6.55)" 2.64 ok Oe 26.96. . 102} in 0-20 |met’rs 1-968: 16) 18.75} 25. 12.50). 6.25) 12750) 2b.) 26 Soe During the fall of 1894 (see Pl. XI) the collections of Daphnia kahlbergiensis were quite uniform in amount, reaching a maximum in the latter part of October. During the winter the number was very small, and they did not become numerous again until June. There is a fall maximum again in 1895 in the latter part of October, but, curiously, the total numbers collected during the fall of 1895 are much smaller than in 1894. During the winter and spring of 1896 Daphnia-was entirely ab- sent from the collections. They appear again about the middle of May, and the largest collections of the year were made from June 29 to July 27. In August and September the collections were rather small, but the number became larger the latter part of October as in the preceding years. Apstein (96, p. 170) states that the species of Daphnia reach their maximum in August, but that D. cederstroemi is somewhat later, so that it would appear that my results in regard to the seasonal distribution of Daphnia do not agree very closely with his. It is probable that the various species of Daphnia may differ considerable in their periods of maximum occurrence. Marsh—Limnetic Crustacea of Green Lake. 211 Daphnia may be found at all depths, but is most numerous in the upper ten meters. In some cases, however, more than fifty per cent. of the catch is below the twenty meter line. Very few Daphnias occur in winter, and I could not distinguish any effect of season on distribution. The averages of the day and night hauls of ’94 were as fol- lows: —_—. 0-5 5-10 10-15 WW OCG OL. ee i aiale'e Moats gk eilo es 38 .39 24.43 15.40 MMe OCs OE) oie sais al aie's:s) alee seta ais, 54.48 23.01 13.46 These averages would seem to indicate a movement towards the surface at night. I am not sure that this inference is war- ranted, however, for the averages are of numbers with wide limits of variation, and I accept the conclusion with consider- able doubt. eeeeecrteeoee es eleseseaes BOSMINA. Per cent. No. | Total obey of Coll.| No. 0-5 | 5-10 | 10-15} 15-20} 20-25] 25-30) 30-35] 35-40) 40- 1.94 9) 89. 76] SAGAR an Sc Uta | eli need Nee] ND eM Os CA AAT 4.94 SAPS, Selle fel St UNA A 5% Ray cal | WEA (| Pt MERION nT A 5.94 TAN APA. 2) OFS hailey (a igh oye Plate VII. Trans, Wis. Acad., Vol. XI. Nov. Mya: Ock, Sot Apr May, Vb, Jon. ANNUAL DISTRIBUTION OF DIAPTOMUS. Plate VIII. Trans. Wis. Acad., Vol. XI. ANNUAL DISTRIBUTION OF HPpiscHuURA LACUSTRIS. revit Cet Neiscah aval 7) at nx Plate IX. Trans. Wis. Acad., Vol. XI. Q oO <4 a) 150 \ 20 ANNUAL Disrripution oF LimnocaLANus Macrurvs. y t ~ 4 “ z . EO PPE ape GRD La Sawing sat! 9 Je < Raye 0 fn Me a ed Pate x: Trans. Wis. Acad., Vol. XI. ANNUAL DISTRIBUTION OF CycLops FLUVIATILIS. Plate XI, Tirans. Wis.sAcad., Wol., x. AARRRAAANP aA PT Tce CTR ANNUAL DisTRiIBUTION OF DAPHNIA KAHLBERGIENSIS. Plate XII. XI. Trans. Wis. Acad., Vol. ANNUAL DisTrRIBUTION OF BosMINA, eae Sabai 2 ta Plate XIII. wrans-e Wis, Acad.; Vol. XG; US CrLosinc DREDGE AND RELEASING APPARAT / te oll “AIX 938Id ‘TX JOA “peoy “SIM “suetL qs We gate igi Es uae Cc. D. a 5 the. ‘Tm etioa : D. minutus und sicilis, deren abwechselnde Haufigkeit (, Wahrend des September gischen Cladoceren*kénnen wir uns kiirzer fassen. -einzelnen Loealitaéten von Fall Ape cay ermittelt sein will. es *, 2 we ce -., sh Wisconsin Acad. of sciences, Vol . Die vom Verfasser behandelten esultate stiitzen Bo ne eine. hae Jahre umfassende Reihe von Untersuchungen - (seit August 1893). In einer Beschreibung des Untersuchungsgebietes wird der Green Lake zu den Dinobryon- Seen gerechnet, ,and yet I have never found Dinobr yon in it*. Verfasser sehlagt —- fiir die nordamerikanischen Seen eine Kintheilung in tiefe (wenn iiber 40 m tief) und seichte Seen vor, und bemerkt, dass die Faunen dieser zwei Classen in ihrem allgemeinen Charakter sehr distinct seien. Fiir die seichten Seen sei wenigstens in den Sommermonaten das Vorkommen chlorophyllfihrender Algen charakteristisch. Die folgenden Seiten bringen eine ausfiihrliche Darstellung des vom Ver- fasser construirten Schliessnetzes, der Fang- und Zahlmethode. Unter den unter- suchten Thieren nimmt der schon durch seine Haufigkeit und seine von den iibrigen Copepoden leicht unterscheidbare Kérperform ausgezeichnete Diaptomus die erste Stelle ein. Wa&hrend die in Europa untersuchten Seen meist immer nur eine Species zu beherbergen scheinen, fand Verfasser im Green Lake den ; und October war D. minutus viel mehr haufig. Im September wurden von D.- sicilis nur sehr wenige gefunden. Im October und November wuchs die relative Menge von D. sicilis, und in den Wintermonaten bestanden die Sammlungen fast aussehliesslich aus D. sicilis.“) zur muthmasslichen “Annahme eines Saison-. dimorphismus fihrte. fs Die Diaptomiden wurden in allen Tiefen gefunden, doch. in den -tieferen Schichten nur in geringerer Anzahl. Verfasser findet weder in den verschiedenen ° Jahreszeiten,’) noch in den Tag- und Nachtfangen einen bedentenden Untersehied (in Bezug auf die Quantitaét), so dass weder tagliche noch jahrliche Wanton eas . angenommen werden kénnen. Bei der Besprechung der tibrigen Copepoden und der untersuchten. pein Epischura meidet helles Licht, zieht warmes Wasser vor und zeigt cows jahreszeitliche als auch tagliche Wanderungen. ee Auch Lamnocalanus meidet helles Licht und hohe Temperatur, eaten seine taglichen verticalen Wanderungen im kalten Wasser ausgesprochener ‘sind. Cyclops brevispinosus ist sehr zahireich zwischen 5 und 20m. Tag- und — Nachtfange gaben fiir ihn keine augenfalligen Unterschiede. | Cyclops flumatilis scheint keine taglichen verticalen Wanderungen nese unternehmen, doch konnte in Bezug auf sein Vorkommen in den verschiedenen Jahreszeiten eine Bevorzugung des warmeren Wassers beobachtet werden. ae | Leptodora ist ein ausgesprochenes Oberflichenthier, doch konnte kein: - entscheidender Beweis, der fiir eine tagliche Wanderung sprechen wiirde, erbracht. werden. Bei Henin Ka ahlbergiensis wurde ein deutliches Aufsteigen gegen die oberflichlichen Wasserschichten zur Nachtzeit beobachtet. Bosmina (Verfasser fihrt in dieser Arbeit leider nicht die Saeoien an) zeigt in ihrem Vorkommen quantitativ keine merklichen Verschiedenheiten in den verschiedenen Jahreszeiten. Ihre nachweisbaren taglichen Meee bier werden durch Phototaxis erklart. Durch Meiden hellen Lichtes dagegen finden wiederum die i Wanderungen der Daphnien ihre Erklarung. ae : ‘Auf Grund dieser Thatsachen sieht sich Verfasser gendéthigt, orton seiner urspriinglichen, vorgefassten Meinung von einer gleichmassigen Bewegung der. = al Crustaceen in ihrer Gesammtheit, bei den einzelnen Genus, bezw. Species ein — verschiedenes Verhalten anzunehmen, das fir die einzelnen Formen wie fir die rar! ') Da, wie wir gesehen, zwer Species im Se vorkommen, die, wie iueniisece selbst. sagt, ‘een nicht gleich verhalten, sind diese Angaben nur ganz allgemein fix das Genus. verwerthbar und Jassen 5 oe Specialuntersuchungen an den einzelnen Arten um so wiinschenswer ther verscheinen. re Sc ae $e : ee 2 Wide seheinen auf lie Varuna ae Enkoninstraaeh keinen qerkli¢hen- = Mites zu haben. Die oben hervorgehobenen Ergebnisse der Untersuchungen — -stehen in Uebereinstimmung mit den Beobachtungen Francé’ s und Birge’s. Ein Schlusseapitel endlich ist der horizontalen Vertheilung der limnetischen | Crustaceen gewidmet. Nach einer tbersichtlichen Zusammenstellung des gegen- wartigen Standes der Frage (Ansichten von Frié ond Vavra, Imhof, Zacharias, — _Apstein, Reighard, Ward) kommt Verfasser anf Grund seiner Untersuchungen ~ gu dem Resultate, dass die Crustaceen des Green Lake keine glciohnasszes _horizontale Verbreitung erkennen lassen. . Zum Schlusse seiner sehr interessanten Ausfiihrungen gibt Verfasser der . 7 - Hensen’schen Zahlmethode vor der einfachen volumetrischen Messung den Vorzug _ Sua fordert zu méglichst genauen und durch lange Zeit fortgesetzten Unter- suchungen auf, die allein im Stande sind, uns ein Klares Bild von der Vertheilung der Organismen zu geben. * Ad. Steuer. Pe W. A. Herdman, J. C. Thompson and A. Seott. 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. L’pool Biol. Soe., Vol. XI, ae Read Nov. 12the 1897. Pl V—VIII.) Herdman benitzte auf seiner Reise zum Sammeln des Plankton kein. Netz, sondern verwendete die schon vor Jahren von Kramer’) im rothen Meee “mit Erfolg in Anwendung gebrachte Pumpmethdde, die ja tberdies auch vor Kurzem von dem verstorbenen Frenzel fiir Siisswasser-Untersuchungen em- pfohlen wurde. Besonderes Interesse muss die nua auch von Herdman wieder hervorgehobene innige Bezichung der Strémungsverhaltnisse zu der Vertheilung ed der Planktonorganismen erregen; Verfasser sagt p. 41 ungefahr: ,Der Einfluss — des Wechsels der Temperatur auf die Organismen war sehr bemerkbar, besonders — im kalten Labradorstrom. .. . Hatten wir kein Thermometer gehabt und auch sonst unsere Position nicht bestimmen kénnen, ich glaube, es wire durch die mikroskopischen Planktonuntersuchungen allein méglich gewesen, Gewissheit aie erlangen, ob wir uns im Labradorstrom befunden hatten oder nicht.“ ee Einem ausfihrlichen Verzeichnisse der einzelnen Fange folgt. eine Liste der von Thompson und Scott bestimmten Copapoden, unter denen sich auch | drei neue Species finden, nimlich Eurythemora herdmani, Corynura discaudata “und Acartia forcipata. Nicht unerwaihnt darf bleiben, dass von dem bekannten, — iiberall vorkommenden Calanus finmarchicus die gréssten Exemplare im Labr ador- 4 strom gefunden wurden und dass diese Form im siidlicheren Theile ‘des North Atlantic yon C. propinquus und tonsus vertreten zu werden scheint. , Endlich kommt Herdman auch auf das Capitel ,Copepoden als Nahrungs- 3 mittel* zu sprechen. Er findet die Thiere, tiber deren Zubereitung schon vor = Zeiten der Prinz von Monaco berichtet, Ausserst schmackhaft und empfiehlt den Fang derselben bei Unglicksfallen auf See (Hungersnoth bei Schiffbruch). a Zum Schlusse_ bringt Herdman ein Verzeichniss der im Puget Sound (Pacific coast) gesammelten Thiere, unter denen Pseudolichomolgus columbiae (n. gen., n. spec.) fiir die Wissenschaft neu ist. . Ad. Steuer, —-- elias. af 7 1 = jae ') Ausserdem von J. Murray, wie Verfasser p. 82 anfabrt. Tr BOE i mae y; i roa k ‘ ~ + SHICh aes ES Il wi!) LUNI 3 9088 00049 1035