343 



Fam. 11. Paramphithoidae. 



Body more or less slender, with well- developed coxal plates, the 3 

 posterior paii's of which are much smaller than the anterior ones. Cephalon 

 produced in front to a more or less projecting rostrum. Eyes normal, placed 

 on eacli side of the cephalon. Antennae generally very slender, with many- 

 jointed flagella, the superior ones longer than the inferior and without any 

 accessory appendage. Anterior lip lamellar and distinctly bilobed at the tip ; 

 posterior lip with the inner lobes scarcely projecting. Mandibles of moderate 

 size, cutting edge coarsel^y dentated, that of the left mandible having a secon- 

 dary dentated lamella, molar expansion more or less developed, palp very 

 large, with the last joint falciform curved. Maxillae of the usual structure, 

 basal lobe of 1st pair rather small. Maxillipeds with the masticatory lobes 

 comparatively small and armed with slender setiform spines, palp rather elon- 

 gated. Gnathopoda more or less powerful, subcheliform, and of similar struc- 

 ture. Pereiopoda normally developed, the 3 posterior pairs of similar struc- 

 ture, with the basal joint laminarly expanded. Branchial lamellae simple and 

 rather small; incubatory lamellaj large. Last pair of uropoda with short 

 basal part and narrow lanceolate dentated rami, the outer of which is much 

 shorter than the inner. Telson very small, iinarmed, hollowed dorsally, tip 

 not incised. Sexual difference very slight. 



BemarJcs. — The present family is chiefly chai'acterised by the slender 

 and elongated superior antennae, the lamellar bilobed anterior lip, the com- 

 paratively small and narrow masticatory lobes of the maxillipeds, finally by 

 the structure of the last ]iair of uropoda and that of the telson. In their 

 external appearance some of the forms bear a considerable resemblance to the 

 Afi/lidce, as defined by Boeck, and 2 of the species described below as belong- 

 ing to the present family, were, indeed, referred by Boeck to his genus 

 Amphithopsis. The family was not adopted by Boeck, who referred the type 

 genus ParampMllwi' to the OEdieerid<E, with which it only shows a very remote 

 affinity. In the restriction here adopted, the family comprises 4 genera (to 

 be described in the sequel), one of which is now for the first time established. 



Gen. 1. Pleustes, Sp. Bate, 1858. 



Syn. ; Paiamphithoe, Boeck (part). 



Body robust, angidar in transverse section, with strongly incrusted 

 integuments, and partly armed with obtuse prominences. Cephalon produced 



