ISOPODS OF NORTH AMEKICA. 



145 



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

 with two small frontal tuJxn-cles rather closer together, and two hirge 

 sul)occipital tubercles more widely separated. The head of the female 

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

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

 articles. " 



EXOCORALLANA TRUNCATA (Richardson). 



CoraZtona ^runcata Richardson, Proc. U. S. Nat. Mus., XXI, 1<S99, p. 825; Ann. 

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



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

 California. 



Bod}^ elongate, about three and a half times longei- than wide; color 

 jxllow. 



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

 distance apart. First pair of antenna', with a Hagellum of al)out nine 

 articles, extend to the an- 

 tero-lateral angle of the 

 first thoracic segment. 

 Second pair of antenniB 

 broken in specimen. 



First segment of the 

 thorax is as long as the 

 head, and a])out one and 

 a half times longer than 

 any of the other seg- 

 ments. Epimera of the 

 second and third seg- 

 ments narrow; those of 



the remaining seo'ments fi«- 128.— exocorallana truncata. a, maxilliped. x 27^. 



1 J (), Mandible, x 27^ c, First maxilla (outer lobe), x 274. 



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 prsecedenti (C tricornis) valde affinis, characteribus sequentibus 

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

 man(lil)ulis obtectum. IMandibularnm pars distalis dimidia sat alte eminens, obscu- 

 rius trilida. Segmentum ultimum ad latera versus paulo magis impressum (piam in 

 specie pran'edente [C. tricornis). 



Mas: Caput ut in specie prseeedente excavatnm, cornibus duobus frontalibus minor- 

 ibus, minus distantibus et cornibus duobus majoribus, suboccni)italibus, magis dis- 

 tantibus ornatum. — Long. 6, 3 mm. 



Femina: Caput ut in specie pra?cedente. — Long. 6, 8 mm. 



Descr. Htec species Cor. tricorni simillima; characteres omnes graviores in diagnosi 

 commemorati sunt. Fra^terea differt cauda minus hirsuta, parte apicali scguienti 

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

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

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



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