PEREZ FARFANTE: AMERICAN SOLENOCERID SHRIMI'S 



basis and usually on ischium. Exopods on all max- 

 illipeds and pereopods. Lateral ramus of uropod 

 armed with distolateral spine, reaching distal 

 margin of lamella (terminal spine). In males, 

 petasma with distal part of ventral costa fused to 

 flexible flap of ventrolateral lobule; distal end of 

 rib of dorsolateral lobule elevated above adjacent 

 area and not projecting beyond distal margin; 

 ventromedian lobule usually produced in con- 

 spicuous processes distally; endopod of second 

 pleopod bearing appendices masculina and in- 

 terna, and with basal sclerite produced distally 

 into elongate, ventrolateral ("posterior") spur. 

 Thelycum of open type, lacking enclosed seminal 

 receptacle. Pleurobranchia present on somites IX 

 to XIV; rudimentary arthrobranchia on somite 

 VII, and anterior and posterior arthrobranchiae 

 on somites VIII to XIII. Podobranchia present on 

 second maxilliped, and epipod on second maxilli- 

 ped (and on first if proximal exite of coxa consid- 

 ered an epipod) through fourth pereopod. 



List of species-Following are the species listed 

 in each of the two sections proposed by Burken- 

 road (1936), a division with which I am in full 

 agreement- 

 Section 1. Pterygostomian spine present. 

 Atlantic, Indo-West Pacific: Hymenopenaeus 

 laeuis (Bate 1881). Indo-West Pacific: Hy- 

 menopenaeus sewelli Ramadan 1938. East- 

 ern Pacific: Hymenopenaeus doris (Faxon 

 1893); Hymenopenaeus nereus (Faxon 1893). 



Section 2. Pterygostomian spine absent. 

 Atlantic: Hymenopenaeus aphoticus Burken- 

 road 1936; Hymenopenaeus debilis Smith 

 1882; Hymenopenaeus chacei Crosnier and 

 Forest 1969. Indo-West Pacific: Hymeno- 

 penaeus aequalis (Bate 1881); Hymenope- 

 naeus fattahi Ramadan 1938; Hymenope- 

 naeus halli Bruce 1966; Hymenopenaeus 

 neptunus (Bate 1888); Hymenopenaeus obli- 

 quirostris (Bate 1881); Hymenopenaeus pro- 

 pinquus (de Man 1907). 



Affinities. -The members of the genus Hymeno- 

 penaeus differ from those of the closely related 

 Haliporoides, Pleoticus, Hadropenaeus n. gen., 

 and Mesopenaeus n. gen., in having a more slen- 

 der body; a thin, flexible, almost membranous in- 

 tegument; the epigastric and first rostral teeth 

 separated from the remaining teeth by an interval 

 longer than the spaces between the more anterior 



teeth; and in possessing a posthepatic carina. 

 They also differ from those of the other genera 

 in having a slender mandibular palp in which the 

 distal article is much shorter than the basal; ex- 

 tremely long and flagelliform fourth and fifth 

 pairs of pereopods, and in certain features of the 

 petasma: the terminal part of the ventrolateral 

 lobule forms a flap to which the ventral costa is 

 fused, the rib of the dorsolateral lobule is elevated 

 distally from the surrounding area, and the 

 ventromedian lobule is produced distally into con- 

 spicuous processes. 



Remarks.-ln the widely utilized work of Kubo 

 (1949) several statements are made which should 

 be discussed. Kubo based his description of the 

 genus Hymenopenaeus primarily on two species 

 found in Japanese waters [H. lucasii (Bate 1881) 

 and H. aequalis (Bate 1888)], which led him to 

 make erroneous generalizations. First, he consid- 

 ered the presence of two, instead of one, arthro- 

 branchiae on somite VII as a character typical of 

 Solenocera, and in his key to the genera of the 

 subfamily Solenocerinae utilized this character to 

 distinguish it from other genera in the subfamily. 

 In at least one species {Pleoticus robustus, pre- 

 viously included in Hymenopenaeus) , of a genus 

 other than Solenocera, however, I find that there 

 are two arthrobranchiae on somite VII. Secondly, 

 Kubo noted that the petasma in "Hymenopenaeus" 

 possessed spinules along the distal margin; actu- 

 ally, in some species they are absent. Finally, in 

 the section "Arrangement of branchiae" Kubo indi- 

 cated the restriction of podobranchia to somite VIII 

 (on second maxilliped) in the members of the sub- 

 family Solenocerinae, and in his table 6D he noted 

 the presence of only one podobranchia in Hymeno- 

 penaeus and Parahaliporus (=Haliporoides). 

 In the key to the genera of the subfamily, how- 

 ever, he utilized the occurrence of a rudimentary 

 podobranchia on somites IX and X as the only 

 feature to distinguish Hymenopenaeus from Hali- 

 porus and Parahaliporus. He used this feature in 

 the key although in the following description of 

 the genus Hymenopenaeus, he stated that in the 

 specimens of H. lucasii and H. aequalis at his 

 disposal, the epipods of none of the thoracic ap- 

 pendages behind the second maxilliped are fur- 

 nished with podobranchia. It thus seems that in 

 the key the line corresponding to Hymenopenaeus 

 and the line corresponding to Parahaliporus and 

 Haliporus were transposed; however, podobran- 

 chiae are present behind somite VIII in Haliporus 



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