19 



The anterior end of the inner lamina of the petasma is very large 

 and covers the anterior end of the outer lamina (PI. VII, 6). 



The color is light red or light brown in adult animals and greyish 

 green in immature animals. 



The animal generally reach maturity when it is about 1 2 cm. in 

 length. Well grown specimens measure 1 8 cm. in length. 



The spawning season is from summer to autumn. 



This species is very widely distributed. It is found from the Tokyo 

 Bay to the southern end of our empire and also along the lower half 

 of the coast of the Japan Sea. 



It is known under the names of "yoshiyebi," '"hozoyebi," "unadori- 

 yebi," etc. 



This species inhabits the shallow water like P. affinis. 



P. monoceros [P. ensis) of de Haan is probably this species ; but 

 the author describes that his species is armed with 3 pairs of spines 

 on the tail segment. P. incisipes, P. affinis, P. monoceros, etc are often 

 confounded. 



PENAEUS JOYNERI. 



(PL V) 



, PenaezLs Joyneri, Miers, On a Coll. of Crust, from the Malayasian 

 Regions, Ann. Mag. Nat. Hist. 5 series v p. 458 (1880). 



The shell thin, soft and with irregular setae-grown grooves. The 

 rostrum slightly curved upward at the anterior end, 7 dentate. Its 

 anterior portion remains toothless and the toothless portion is subequal 

 in length to that of the eye. A faint median kiel in the carapace is 

 continuous to the rostrum and there is moreover a faint ridge between 

 the hepatic tooth and the posterior margin of the carapace as in P. 

 incisipcs. The second joint of the first to the third pereiopoda unispinose. 

 In males, the spine of the third pereiopoda is enormously developed 



