l'KRKZ KARKANTK: AMERICAN SOLENOCKRII) SHRIMI'S 



pereopods are missing. Kubo (1949) considered 

 that H. malhaensis and H. lucasii are distinct 

 species; he stated that his specimens of//, lucasii 

 cannot be referred to H. malhaensis because in 

 the latter there are 3 teeth on the carapace, the 

 scaphocerite does not overreach the antennular 

 peduncle, and the dorsal antennular fiagellum is 

 not longer than the ventral which also lacks 

 "rather long setae" on the dorsal and ventral bor- 

 ders. Actually, the first two features are not typi- 

 cal of H. malhaensis but occur in H. lucasii, in 

 which, as stated above, 3 teeth may be present on 

 the carapace, and the scaphocerite, which usually 

 overreaches the antennular peduncle, extends 

 only to the distal end of the peduncle in some 

 individuals. Features of the antennular fiagella 

 of H. malhaensis cited by Kubo could be due to 

 the fact that the dorsal fiagellum was incomplete 

 in the type, as it often is in preserved specimens, 

 or to omissions of the artist. The two species dis- 

 cussed seem to me to be quite similar, and if there 

 is doubt in my mind as to the status of//, malhaen- 

 sis, it is mainly because of Borradaile's statement 

 that the fourth and fifth pereopods are not "par- 

 ticularly slender." The species exhibits most of 

 the features of Hadropenaeus: stout body, thick 

 carapace, short rostrum with ventral margin con- 

 vex, middorsal teeth on the carapace separated by 

 regularly decreasing intervals, lack of branchio- 

 cardiac carina and sulcus, and relative length of 

 the last two pereopods having "fourth leg rather 

 longer and fifth considerably longer than the 

 third." These features of Hadropenaeus combined 

 with a fifth pereopod that is not very slender, how- 

 ever, are unique. Perhaps the question of the 

 identity of Borradaile's species will be resolved 

 when large collections of solenocerids from the 

 Indian Ocean are studied. Meanwhile, I am 

 inclined, tentatively, to assign H. malhaensis to 

 the synonymy of H. lucasii. 



Mesopenaeus New Genus 



Parartemesia Bouvier 1905b:747 [part, excluding 



Parartemesia carinata Bouvier 1905b = Pleoti- 



cus muelleri (Bate 1888)]. 

 Haliporus. Bouvier 1906b:l [part]; 1908:78[part]. 



A. Milne Edwards and Bouvier 1909:206 [part]. 

 Hymenopenaeus. Burkenroad 1936:102 [part]. 



Roberts and Pequegnat 1970:29 [part]. 



Diagnosis- Body stout, carapace proportionately 

 short; integument thick, firm. Rostrum short, 



reaching approximately to base of second anten- 

 nular article; deep, with ventral margin pro- 

 nouncedly convex, and armed only with dorsal 

 teeth; epigastric tooth and first rostral separated 

 by interval similar to that between first and sec- 

 ond rostra] teeth. Orbital, postorbital, antennal, 

 and hepatic spines present; pterygostomian and 

 branchiostegal spines absent. Cervical sulcus 

 long, almost reaching middorsum of carapace; 

 hepatic sulcus deep; branchiocardiac carina and 

 sulcus, posthepatic, and submarginal carinae 

 lacking. Abdomen carinate dorsally from third 

 through sixth somites. Telson with pair of con- 

 spicuous, fixed lateral spines. Prosartema long, 

 flexible. Antennular flagella not much longer 

 than carapace and dissimilar: dorsal fiagellum 

 subcylindrical and slender, ventral one conspicu- 

 ously depressed. Mandibular palp two jointed, 

 articles broad, distal one almost as long as basal 

 and tapering to blunt apex. First maxilla with 

 unsegmented palp (endite of basis) gently narrow- 

 ing to rounded apex. Fourth and fifth pereopods 

 rather stout proximally, fifth moderately longer 

 than fourth. First pereopod with spine on basis 

 and ischium. Exopods on all maxillipeds and per- 

 eopods. Lateral ramus of uropod armed with disto- 

 lateral spine reaching distal margin of lamella 

 (terminal). In males, petasma with ventral costa 

 not projecting free distally, there bearing flexible 

 flap; distal portion of rib of dorsolateral lobule 

 projecting beyond margin of adjacent area; endo- 

 pod of second pleopod bearing appendices mascu- 

 lina and interna, and with basal sclerite produced 

 distally into long ventrolateral spur. Thelycum of 

 open type, lacking enclosed seminal receptacle. 

 Pleurobranchia on somites IX to XIV; single, 

 rudimentary arthrobranchia on VII, and anterior 

 and posterior arthrobranchiae on somites VIII to 

 XIII; podobranchia on second maxilliped, and epi- 

 pod on second maxilliped (and on first if proximal 

 exite of coxa considered an epipod) through fourth 

 pereopod. 



Type-species.-Parartemesia tropicalis Bouvier 

 1905b. 



Etymology. -The generic name is derived from the 

 Greek mesos, something in between, in combina- 

 tion with the generic name Penaeus, alluding to 

 the fact that the dorsal antennular fiagellum is 

 subcylindrical and filiform, as in Pleoticus, Hali- 

 poroides and Hymenopenaeus, and the ventral 

 one flattened, much as in Solenocera. 



331 



