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i . Cleistostoma dilatatum de Haan. 



1835. Ocypode 'Cleistostoma) dilatata de Haan. Faun. Japon., Crust. p. 55, pi. 7, f. 3. 

 1852. Cleistostoma dilatata H. Milne-Edwards. Ann. Sc. Nat. (3) t. iS, p. 160. 

 1895. Cleistostoma dilatatum de Man. Zool. Jahrb., Syst., Bd 8, p. 595 (note). 



In comparing the only specimen of de Haan in the Leiden Museum with the original 

 Aa-ure it is evident that this is the very specimen from which de Haan took his observations 

 and consequently his drawing is wrong in representing the carapace too long and the front 

 too broad, whereby I only affirm de Man's statements; this latter author has furnished us with 

 measurements. De Haan is also wrong in stating that the lateral margins of the carapace are 

 entire, not granulate; in reality they are finely and regularly beaded throughout. 



This species has much in common with Alcock's Cl. dotilliformc, but is relatively 

 much broader (maximum breadth of carapace 1,53 times the length in the former and 1.32 in 

 the latter species). In both species the shape of the meropodites of the ambulatory legs is 

 equally foliaceous, and in both the anterior margin of the perfectly flattened and naked upper 

 surface of the meropodites is marked by a granulate row, at least in the case of the first to 

 third pair of legs. From the point where the carapace reaches its maximum breadth in 

 Cl. dilatatum a granulate and hairy row runs obliquely backward on the subbranchial region to 

 the bases of the second pair of walking legs, thus marking off dorsally a triangular facet, as 

 Miss Rathbun describes in Cl. lingulatum. The pterygostomial regions are much like that ot 

 Alcock's species, but in Cl. dilatatum there is an additional sulcus, running transversely, 

 immediately below the infra-orbital border, which latter is finely and regularly crenulate, not in 

 the coarse way as represented in Cl. dotilliforme. The external maxillipeds (figured by de Haan 

 on pi. B) again closely agree with those of the latter species : the merus is large, quadrate, 

 not narrowing anteriorly (as in Cl. lingulatum) ; the sulci on the surface are perfectly alike in 

 both species- the ischium has an obliquely-transverse, very narrow groove close to the anterior 

 margin and the antero-internal angle is produced into an obtuse prominence; the exognath is 

 only partly exposed in outer view. The eye-stalks are thick, slightly shorter than the breadth 

 of the front betweeh the bases of these eye-stalks. 



Paracleistostoma de Man. 



1895. Paracleistostoma de Man. Zool. Jahrb., Syst., Bd 8, p. 580. 



Four species belong to this genus, and a fifth one has been added by the "Siboga" expediton. 

 Key to the species : 

 1 . Palm of cheliped of c? with a superior and an inferior longitudinal 

 granulate crest. Ambulatory legs covered with a close fur of 



long, yellow hairs ■ P. eriophorum Nobili \) 



Palm of cheliped smooth, without crests. Ambulatory legs nor- 

 mally hairy 2 



1) Boll. Mus. Torino, t. 18, I903, n" 447, p. 23. Hab. Buntal (Borneo). 



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