17:2 



2. The angles of the orbit:il sinuses are smooth : most of the carinte 

 of the abdominal terga are deeply notched : 



i. Ciirapace depressed : the abdominal terga and pleura 



with a very few scattered vesiculons granules .... P. Carpenteri. 



ii. Carapace decidedly convex : the abdominal terga and 



pleura with sharp miliary tubercles ... ... P. gihlm*. 



100. Pentacheles Hextii, Alcock. 



reiitachcles Hextii, Alcock, Ann. Slag. Nnt. Hist., March 1894, p. 237. 



ILLUSTRATIONS OF THE ZOOLOGY OF THE INVESTIGATOR, CRUSTACEA, PLATE X. FH;. 2. 



Carapace covered with a hairy tomentum, beneath which it is beset every- 

 where with spinules and sharp granules in addition to certain definitely placed 

 spines. 



Carapace elongate-quadrilateral, depressed, its lateral borders nearly parallel 

 except at the fonr corners, its length about half a telson-length less than that 

 of the abdomen. Its frontal border is concave, and in addition to a simple 

 rostral spine and to a strong spine at the inner angle of either orbital notch and 

 another at the frontal end of either impacted eye-stalk, is armed with several 

 spines at either outer orbital angle. The orbital notches are quite peculiar in 

 being divided each into two portions by a serrated lobe that stretches across 

 from the inner border of each, the anterior portion contains the calcified part, 

 the posterior portion contains the thin translucent part of the eye-stalk. 



The lateral borders of the carapace are armed with from 26 to 31 spines, 

 namely, 7 or 8 + 5 in front of the cervical groove and 14 to 18 of gradually 

 diminishing size behind it. The posterior border is armed with some antrorse 

 spines. 



The dorsal carina begins in a simple rostral spine and ends in a pair of 

 spines on the posterior border of the carapace: it is closely and sharply granular 

 with some irregularly disposed spines of larger size, and behind the cervical 

 groove is distinctly double. 



On either side of the carapace a line of spines behind the orbital notch 

 defines the gastric region, and a closely-spinose ridge runs parallel with the 

 posterior half of the lateral border. The ridge also that defines the cervical 

 groove is spinose. 



The abdominal terga and pleura have their edges serrated and their surface 

 more or less studded with vesiculous granules. All the terga are longitudinally 

 carinated in the middle line: the carina of the 1st is faint and hardly distin- 

 guishable from the neighbouring serrations, that of the 6th is granular and 

 double, those of the 2nd 5th are sharp and culminate anteriorly each in an 

 antrorse spine. 



