FOUR NEW SPECIES OF ISOPODS FROM THE COAST OFCALIP^ORNIA.
By S. J. Holmes and M. E. Gay,Of the Universitij of Wisconsht, Madison.
The specimens of the new species here described were collected onthe coast of California by Dr. S. J. Holmes and sent to the U. S.National Museum.ANCINUS GRANULATUS, new species.Body very broad and much depressed, contractile, evenly anddensely granulated. Thorax with parallel sides. Head twice asbroad as long; front produced into a recta.ngular lobe between thebases of the antennules ; a small lobe on theanterior margin on either side of the medianone. Eyes small and round.Antennae nearly equal in length; thejflagellum of the first somewhat longer thanthe peduncle and composed of about 10joints. Second antennae with the flagellumabout 10-jointed and longer than the pe-duncle; both furnished withsetse having a brush of radiatinghairs at the tip.Mandibles with the pa,lp situ-ated behind the middle, the lasttwo joints furnished on the dis-tal part of the outer marginwith setose spines, those of thelast joint increasing in length toward the tip. Palp of the maxilli-peds with the first joint very short, the second and third joints aswide as long and produced into a rounded setose lobe on the innermargin ; fourth joint produced at the distal end of the inner margininto a rounded setose lobe; last joint oblong, distally rounded andsetose, and about three-fourths the length of the preceding one.
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Fig. 1.
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Ancinus granulatus ; j/?,, firstGNATHOPOD.
Proceedings U. S. National Museum, Vol. XXXVI?No. 1670. 375
ste PROCEEDINGS OF THE NATIONAL MV8EUM. VOL. xxxvi.First pair of legs with a broad hand having a very convex anteriormargin; pahn comprising nearly all the posterior margin of thehand, evenly curved, and furnished with a long spine at the upperend. The following legs increasing in length posteriorly and fur-nished on the marginswith long spines and finecilia.First abdominal seg-ment very short. Termi-nal segment triangularwith slightly sinuous mar-gins, the tip narrowlyrounded when seen fromabove, but having a deepnotch on the lower side.Uropods with a singlemovable, styliform ra-mus, which nearly or({vute reaches the tip ofthe abdomen.Lengthy 8 mm.Locality.?Near Coro-nado Island, California,from a depth of 3 fathoms.Tijpe.?Cat. No. 39046,U.S.N.M.This is the only species of the genus known to occur on the Pacificcoast. It is broader and flatter than Ancinus depressns Say of thecoast of New Jersey and has a more broadh^ tri-angular terminal segment of the abdomen.TYLOS PUNCTATUS, new species.Oblong, covered with scattered short spines oracute granulations. Ej^es nearly round. Firsantenna? single jointed, scale like. Second anten-nae less than one-fifth the length of the bod}^, nolreaching the middle of the first thoracic segment
:
a hook-like process on the second joint of thepeduncle ; third joint nearly as long as the twopreceding; flagellum slightly longer than the lastjoint of the peduncle, the third joint nearly aslong as the two preceding; fourth joint short,conical, and furnished with numerous seta? at itsdistal end. Lateral lobes of the head with two triangular projections in front of the eyes.
Pig 2.
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Ancinus granulatus ; a, second legSECOND PLEOPOD OF THE MALE. THESE FIGURES^WHICH WERE KINDLY SIPPLIED BY MiSS II. RICH-ARDSON, ARE DRAWN TO A LARGER SCALE THAN THEPRECEDING ONES.
Fig. 3.
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Tylos punc-TATUS.
K'o. 1670. POVR NEW 8PECIE8 OF I80P0DS?HOLMES AND GAY. 377
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Thoracic segments siibeqiial, the epimera in all produced back-ward and rounded at the posterior antjle. Legs very spiny, theterminal part of the clawmarked off by an apparentsuture from the longer basalportion : first pair of legs withan acute lobe near the distalend of the anterior margin ofthe second joint ; fourth jointproduced and rounded in front.Third abdominal segmentand to a less extent the fourthproduced backward at the outerposterior angle ; lateral processof fifth segment small. Lastsegment truncated and four orfive times as broad as long.Uropods nearly semicircularin outline, armed with a fewscattered spines, the small ter-minal joint furnished with afew spines and several setae.Length, 10 mm.Locality.?San Diego, Cali-fornia, in sand near the beach.Xyne. Cat. Xo. 39047 ^'*^- "*?
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Tylos punctatcs ,- a, AXTEXXA ; mx-i,,
-T-r (<-irr ~Kr ' FIRST MAXILLA; mxp, MAXILLIPED ; plPl,U.O.jN.JM. second pleopod of the male; plpi, fourthXo other representative of pleopod ; m-, cropod.the family Tylidae is known from the west coast of Xorth America.ACTONISCUS TUBERCULATUS, new species.Body elliptical in outline and furnished with small tubercles.Head deeply inserted, with an acute median lobe and prominentrounded lateral ones. Eyes oval. Antennae not one-third the lengthof the body, the second joint of the peduncle a little longer than thethird and about twice the length of the first ; fourth joint longerthan the third but not quite so long as the fifth : flagellum with fourevident joints and a minute terminal fifth joint. The peduncleis bent between the second and third, and the fourth and fifth joints.Maxillipeds with a rounded .setose inner lobe ; palp short andbroad, the first joint much wider than long, the second triangularwith slightly lobulated inner margin, the tip with a brush of longsetae.Legs similar, spiny, a long ciliated spine on the lower margin ofthe fifth joint.
3V8 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXTl.Basal joint of iiropods large, similar to the coxal plates of the pre-ceding segments, and setose on the distal margin; rami extendingabout to the tip of the peduncle, the outerone inserted at the middle of the inner mar-gin of the basal plate, the inner one near thebase; both tipped with seta:>.Lengthy 3.25 mm.Locality.?San Diego, California, on moistground near the seashore.Type.?Cut. No. 39048, U.S.N.M.This species seems to be closely allied toActoniscus ellipticus Harger from the At-lantic coast. The body is somewhat broaderand the lateral processes of the segments aremore nearly rectangular in outline, espe-ciallj^ in the abdomen, and more prominent.PHILOSCIA RICHARDSON^ffi, new species.
Fig. 5.
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Actoniscds tdber-CULATUS. Body oblong-oval, covered with shortminute spinules. Head twice as wide aslong ; frontal margin arched ; lateral angles subacute. First thoracicsegment longer than the following ones, the last three segments pro-duced backwards at thelateral angles. Antennaeabout one-half as long asthe body, the last joint ofthe peduncle about as longas the third and fourth;flagellum t r i articulate,nearly as long as tliP fifthjoint of the peduncle, thefirst and third joints sub-equal and a little longerthan the second; last jointending in a spine.Legs similar, increasinggradually in length frombefore backwards, and veryspiny.Abdomen abruptly muchnarrower than the thorax,the lateral angles of thethird, fourth, and fifth seg-ments produced backwards
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last segment over twice as broad as long, with the posterior marginconcave on either side of the, narrowly rounded tip. Basal joint ofFig. 6.
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Philoscia richardson.e.
No. 1670. FOVR NEW fiPECIES OF I^OPODS?HOLMES AND GAY. 379the uropods about as broad as long; outer ramus slender, acuminate,subconical, with the outer margin nearly straight and the inner onesomewhat convex; inner ramus about one-third the length of theouter, subconical, with narrow blunt tip which is armed with one ormore sharp spines; scattered short spines occur on both rami.Length, 5 mm.Locality.?San Diego, California, on moist swampy ground.Type.?CoX. No. 39049, U.8.N.M.Named after Miss Harriet Richardson, who has contributed somuch to our knowledge of the North American Isopoda.