28 PROCEEDINGS OF THE NATIONAL MUSEUM vol. im 



the telson and has one or more tubercles lateral to these rows. In 

 addition, adults of S. massavensis may have the dorsal surface of the 

 telson ornamented with curved rows of carinae between the curved 

 rows of pits; most of the dorsal surface of the telson in S. hesperia 

 is smooth. 



In the holotype of S. hesperia the anterior lobe of the lateral process 

 of the sixth thoracic somite is slenderer than that found in any of the 

 specimens of S. massavensis examined. 



Judging from the accounts of Kemp (1913) and Serene (1954), 

 specimens identified as S. massavensis from outside of the Red Sea 

 do not belong to that species. I have seen small specimens of a Squilla 

 from the Persian Gulf in which the submedian carinae of the fourth 

 abdominal somite are unarmed and which also differ from S. massaven- 

 sis in having dark dorsal patches on the second and fifth abdominal 

 somites. It seems likely that specimens reported in the literature as 

 S. massavensis from localities outside of the Red Sea belong to S. 

 hesperia or to one or more undescribed species. 



The records of Miers (1880), Kemp (1913), and Ingle (1963), all 

 based on the same two specimens from Zanzibar, are included tenta- 

 tively in the synonomy of S. hesperia; these two specimens must be 

 reexamined. 



Etymology.- — The name is derived from the Latin, "hesperius," 

 meaning "western." 



Distribution. — -Known only from the type-locality. 



Squilla mauritiana Kemp, 1913 



Figure 9 



Squilla mauritiana Kemp, 1913, p. 68. 

 Squilla juxtaoratoria Ward, 1942, p. 55. 



Previous records. — None. 



Material. — 1 9, 102.0; lie Europa, off Madagascar; P. Four- 

 manoir; USNM. 



Description. — Eye of moderate size, cornea bilobed, set obliquely 

 on stalk; eyes not extending to end of first segment of antennular 

 peduncle; anterior margin of ophthalmic somite rounded, faintly 

 emarginate along midline; ocular scales obliquely truncate; corneal 

 index 397. 



Antennular peduncle shorter than carapace; dorsal processes of 

 antennular somite triangular, apices acute, directed anterolaterally. 



Antennal scale slender, curved, about three-fifths as long as cara- 

 pace. 



Rostral plate slightly broader than long, appearing elongate, with 

 upturned lateral margins; apex rounded; median tubercle present on 

 dorsal surface. 



