DESCRIPTION OF A NEW TERRESTRIAL ISOPOD FROMGUATEMALA.By Harriet Richardson,Collaborator, Division of Marine Invertebrates, U. S. National Museum.
The isopod to be described resembles in general appearance and inits spiny armature the form described by Kinahan, from Jamaica, asAcanthoniscus spiniger. Notwithstanding the striking superficialsimilarity of the two species, they can not be referred to the samegenus. Family AR^IADILLIDID^.GLOBARMADILLO, ne^A^ genus.Body covered with long spines. Head wider than long; eyesdistinct.Second pair of antennae with a flagellum composed of two articles,the first being very short.Thorax with no epimera distinctly separated from the segmentseither above or on the under side.Abdomen with the terminal segment triangular, ending posteriorlyin an acute apical point.LTropoda with the basal article or peduncle wider than long, situ-ated somewhat oblic[uely; the inner branch is inserted at the innerpost-lateral angle of the basal article; the outer branch is short,hidden in a dorsal view, and does not reach the tip of the terminalabdominal segment.The type of the genus is Gloharmadillo armatus, new species.GLOBARMADILLO ARMATUS, new species.Body contractile, capable of being rolled up into a ball. Surfacecovered with long spines.Head broader than long, with the front slightly excavate and theantero-lateral angles acutely produced. There are six long spineson the head, tw^o just back of the anterior margin, close together,one on either side of the median line, and four on the posterior halfof the head between the eyes, two on either side of the median line,
PROCEeDiNQ$ U. 3. Nationau Museum, Vou 37?No. 1718. 495
496 PROCEEDINGS OF THE NATIONAL MUSEUM. VOL. XXXVII.the two middle ones being farther apart and longer than those onthe anterior portion of the head. The eyes are small, composite, andsituated close to the lateral margin. The first pair of antennae isinconspicuous and rudimentary. The second pair has the first arti-cle of the peduncle short; the second is much longer; the third isnot so long as the second; the fourth is twice as long as the third;the fifth is a little longer than the fourth; the flagellum consists oftwo articles, the first of which is minute, the second long and taperingand furnished with a long spine at the tip.The first segment of the thorax is furnished with ten long spinesand two small ones. There are two long spines close together onthe anterior portion, one on either side of the median line, six longspines on the middle portion, three on either side of the medianline, and two long ones on the posterior por-tion, close together, one on either side of themedian line. There are two short spinesjust anterior to the two long spines on theposterior portion. The lateral parts of thefirst segment are produced anteriorly andposteriorly into a wide plate on either side.The second segment is furnished with eightlong spines and two short ones. Six of theselong ones are arranged in a transverse rowabout the middle, three on either side ofthe median line, and two are placed nearthe posterior margin, close together, one oneither side of the median line. The twosmall spines are placed just in front of thetwo long ones near the posterior margin.In the following five segments the spinesare the same in number and arranged inthe same manner as in the second segment. The lateral parts of allsix segments are produced into long narrow spine-like processes.Ei)imera are not distinct on any of the segments either on the dorsalor ventral side.The first two segments of the abdomen are short and unarmed;their lateral parts are covered by the last thoracic segment; the fol-lowing three segments are furnished each with two spines closetogether, one on either side of the median line, those on the third andfourth segments being short and those on the fifth segment long.The lateral parts of the third, fourth, and fifth segments are pro-duced in long, narrow tapering processes. The sixth or terminalsegment is triangular, broad at the base and with the posterior marginacutely produced in the middle. The basal, portion of the segment
GLOBAKMADILLO AKMATUS (DIA-GRAMMATIC).
NO. 1718. -1 ^'EW I&OrOD FROM GUATEMALA?RICHARDSON. 497is furnished with two long spines. The uropocla occupy all the spacebetween the lateral parts of the fifth segment and the apical part ofthe sixth segment.The peduncle is large, somewhat obliquely placed, and has the outerbranch inserted along the inner margin. The inner branch does notextend beyond the tip of the abdomen and is concealed by it. Theouter branch is also short and does not extend beyond the apicalprocess of the last abdominal segment.There are seven pairs of ambulatory legs.Only two specimens of this species were collected by Dr. O. F.Cook at Trece Aquas, Guatemala.Type-specimen.?Cat. No. 40082, U.S.N.M.The two specimens are very small and so completely rolled upthat only a diagrammatic drawing could be made.Proc.N.M.vol.37?09 32