3. Ventral antennular flagellum conspicu- 



ously depressed, orbital spine pres- 

 ent Mesopenaeus 



Ventral antennular flagellum subcylin- 

 drical, occasionally depressed, if so or- 

 bital spine lacking 4 



4. Epigastric tooth separated from first 



rostral by interval not conspicuously 

 smaller or greater than that between 



first and second rostral teeth 5 



Epigastric or epigastric and first rostral 

 teeth separated from remaining teeth 

 by relatively long interval 6 



5. Rostrum low, with ventral margin 



straight or concave; submarginal ca- 

 rina present Plcoticus 



Rostrum deep, with ventral margin pro- 

 nouncedly convex; submarginal carina 

 absent Madropenaeus 



6. Epigastric and first rostral teeth sepa- 



rated from remaining ones by long in- 

 terval; suprahepatic spine absent .... 



Hymenopenaeus 



Epigastric tooth separated from rostral 

 teeth by long interval; suprahepatic 

 spine present Ualiporoides 



Hymenopenaeus Smith 1882 



Haliporus Bate 1881:185 [part, excluding Hali- 

 porus curvirostris Bate 1881]. Bate 1888:284 

 [part]. Faxon 1893:213 [part]; 1895:189 [part]. 

 Alcock 1901:22 [part]. Bouvier 1906b: 1 [part]; 

 1908:78 [part]. A. Milne Edwards and Bouvier 

 1909:206 [part], de Man 1911:31 [part]. Fowler 

 1912:542 [part]. 



Hymenopenaeus Smith 1882:91 [type-species by 

 monotypy, Hymenopenaeus debilis Smith 1882. 

 Gender, masculine. Placed on the Official List 

 of Generic Names in Zoology as Name No. 1816, 

 International Commission on Zoological No- 

 menclature (1969), Opinion 864]. Smith 1885: 

 179 [part]. Burkenroad 1936:102 [part]. Kubo 

 1949:212 [part]. Holthuis 1962:108. Inter- 

 national Commission on Zoological Nomen- 

 clature 1969:139. Roberts and Pequegnat 1970: 

 29 [part]. 



Diagnosis. -Body slender, carapace elongate, 

 integument thin, flexible. Rostrum variable in 



FISHERY BULLETIN: VOL. 75, NO. 2 

 lateral process- 

 mesial 

 process 



ventrolateral 

 lobule 



dorsolate ra I 

 lobule 



vent romed la n 

 lobule 



ventral costa 



cincinnul i 



dorsomedian 



lobule 



FIGURE 2. — Left half of petasma (dorsal view) of Hymeno- 

 penaeus debilis showing terms used in descriptions. 



length, reaching between distal 0.25 of first anten- 

 nular article and end of peduncle; ventral margin 

 straight; usually armed only with dorsal teeth, 

 occasionally also with ventral teeth; epigastric 

 and first rostral teeth separated from remaining 

 teeth by relatively long interval. Orbital spine 

 absent; postorbital, antennal, hepatic, and 

 branchiostegal spines present; pterygostomian 

 spine present or absent. Cervical sulcus deep, 

 long, extending to, but not across, middorsum of 

 carapace; hepatic sulcus well marked; branchio- 

 cardiac carina sharp, accompanying sulcus deep; 

 posthepatic and submarginal carinae present. Ab- 

 domen carinate dorsally at least along posterior 

 three somites. Prosartema moderately long, flex- 

 ible. Telson with pair of conspicuous fixed, lateral 

 spines. Antennular flagella similar, filiform, and 

 longer than carapace. Mandibular palp two- 

 jointed, articles relatively narrow, distal one 

 much shorter than basal, and tapering to blunt 

 apex. First maxilla with unsegmented palp 

 (endite of basis), gently narrowing to rounded 

 apex. Fourth and fifth pereopods extremely long 

 and flagelliform. First pereopod with spine on 



266 



