ISOPODS OF NORTH AMERICA. 



145 



The male has the head excavated as in E. tricornis, and ornamented 

 with two small frontal tubercles rather closer together, and two large 

 suboccipital tubercles more widely separated. The head of the female 

 is as in E. tricornis. The flagellum of the second pair of antennae in 

 the male is composed of sixteen articles; in the female of about twenty 

 articles. a 



EXOCORALLANA TRUNCATA (Richardson). 



Corallana truncata RICHARDSON, Proc. U. S. Nat. Mue., XXI, 1899, p. 825; Ann. 

 Mag. Nat. Hist. (7), IV, 1899, pp. 165-166. 



Localities. Catalina Island, California; off Magdalena Bay, Lower 

 California. 



Body elongate, about three and a half times longer than wide; color 

 yellow. 



Head with a small median point. Eyes large, situated but a little 

 distance apart. First pair of antennae, with a flagellum of about nine 

 articles, extend to the an- 

 tero-lateral angle of the 

 first thoracic segment. 

 Second pair of antennas 

 broken in specimen. 



First segment of the 

 thorax is as long as the 

 head, and about one and 

 a half times longer than 

 any of the other seg- 

 ments. Epimera of the 

 second and third seg- 

 ments narrow; those of b c 



the remaining segments FlG - 128. EXOCORALLANA TRUNCATA. a, MAXILLIPED. x 27}. 



6, MANDIBLE, x 27 J. c, FIRST MAXILLA (OUTER LOBE), x 27|. 



very broad. 



The first abdominal segment is almost entirely covered by the last 

 thoracic segment. The second, third, and fourth segments are 



The above description is adapted from the following one of Hansen's: 



Diagn. Speciei praecedenti (C. tricornis) vakle affinis, characteribus sequentibus 

 imprimis differt. Clypeus, infra visus, perangustus et ex parte obtectus; labrum a 

 mandibulis obtectum. Mandibularum pars distalis dimidia sat alte eminens, obscu- 

 rius trifida. Segmentum ultimum ad latera versus paulo magis impressum quam in 

 specie preecedente (C. tricornis). 



Mas: Caput ut in specie prsecedente excavatum, cornibus duobus frontalibus minor- 

 ibus, minus distantibus et cornibus duobus majoribus, suboccipitalibus, magis dis- 

 tantibus ornatum. Long. 6, 3 mm. 



Femina: Caput ut in specie prsecedente. Long. 6, 8 mm. 



Descr. Haee species Cor. tricorni simillima; charac^eres omnes graviores in diagnosi 

 commemorati sunt. Pneterea differt cauda minus hirsuta, parte apicali segment! 

 ultimi minus convexa, spinis tamen 4 apicalibus ornata. (Flagellum antennarum 

 in mare 16 articulatum, in femina c. 20 articulatum.) HANSKN, Vidensk. Selsk. 

 Skr. (6), V, 1890, p. 382. 

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