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i. Halicarcinus planatus (Fabricius). PI. i, Fig. 2. 



Literature: STEBBING, Proc. Zool. Soc. London, 1900, p. 524, pi. 36 B, and Transact. R. Soc. 

 Edinburgh, v. 50 prt 2, 1914, p. 271. 



In the collection of the Leiden Museum is an adult specimen (here figured), unfortunately 

 without locality; besides I have examined 3 specimens, belonging to the Amsterdam Museum, 

 collected by the late Dr. J. H. Kruimel at Port San Pedro (south of Valdivia, Chile) in April 

 1909. All these animals are females. 



The drawing here given and the detailed account of Stebbing may, I hope, dispense 

 me with a full description. Here I shall only remark the following facts : 



i° The carapace is markedly transverse, broader than long; the side walls are obliquely-sloping 

 down to the bases of the walking legs, but anteriorly they are perpendicular; there are two 

 rather sharp but short teeth on either side of the side walls, placed beneath the bordering 

 rim of the flattened part of the carapace and not attached to it. On the carapace there 

 is one distinct groove, viz. the cervical one, and two short, radiating ones, parting from 

 either end; the anterior is continued forward and marks off very feebly the gastric region; 

 from this anterior groove two diverging lines on either side of the carapace are directed, 

 one to the first, the other to the second lateral tooth. Here and there some minute granules 

 are observed on the upper part of the carapace. 

 2" There is no rostrum proper, but beneath the anterior part of the rim, circumscribing the 

 flattened part of the carapace, there are three exactly alike, obtuse, hairy teeth, the median 

 being placed slightly above the level of the lateral ones; in the wide interspaces of these 

 teeth the antennulae are largely projecting forward. 

 3 The eye-stalks are short and thick; the orbital margin is continuous, except for a scarcely 

 prominent, obtuse external orbital angle; below the orbit is incompletely closed by the very 

 thick basal joint of the antennae, that is fused with the surrounding parts immediately below 

 the external orbital angle, and is somewhat produced at the antero-external angle. The 

 antennae are short, reaching at most to the end of the penultimate peduncle-joint of the 

 antennulae; the latter are not separated by a median septum at the base 1 ), the basal joint 

 is very short and thick, freely movable, and reaches as far as the teeth of the rostrum. 

 4" An epistome is present. The external maxillipeds are rather broad, not gaping (though not 

 completely fitting together), covered with club-shaped hairs at outer surface and fringed 

 with yellow hairs at inner margin; ischium broader than merus, but of equal length; carpus 

 implanted at antero-external angle of the merus. These maxillipeds and other mouth-parts 

 are figured accurately by Stebbing 3 ). 

 5" Chelipeds (of Q) rather weak, equal; palm swollen, length equal to that of fingers; the 

 latter straight, finely serrated at inner margin; palm somewhat granular upward and some- 

 what hairy at outer surface. Ambulatory legs short, first pair being the longest (about twice 

 the length of the carapace), diminishing in length posteriorly, nearly smooth, but which a very 



1) STEBBING (1. c, 1900, p. 525) notes a median septum separating the antennules. 



2) L. c. pi. 36 B. 



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