20 



It also differs from Peneus in having an epipoclite to all the thoracic 

 appendages except the last, and in having a pair of arthrobranchiae, instead of 

 only a single (posterior) arthrobranch to the penultimate thoracic somite (XIII). 



So far as Indian species of both genera go, Solenocera further differs from 

 Peneus in the slender, filamentous, almost rudimentary form of the exopodites 

 of the 2nd and 3rd maxillipeds. 



The branchial formula is as follows : 



Total l + 7ep. 6 6 6 = 19 + 7 ep. 



4. Solenocera Hextii, Wood-Mason. 



Solenocera Hextii, Wood-Mason, Ann. Mag. Nat. Hist., Jan. 1891, p. 188, and Oct. 1891, p. 275 : Alcock and 

 Anderson, Journ. As. Soc. Bengal, Vol. LXIII. pt. 2, 1894, p. 145. 



ILLUSTRATIONS OF THE ZOOLOGY OF THE INVESTIGATOR, CRUSTACEA, PLATE XXVI. FIG. 5. 



Glabrous, polished. Rostrum deep, ascendant, armed dorsally with 7 

 teeth, produced as an extremely well-marked carina almost to the posterior 

 border of the carapace, its tip, in both sexes, reaches only to the end of the basal 

 joint of the antennular peduncle. 



Cervical groove and its tributaries deep-cut, interrupted only at the rostral 

 carina. A very deep-cut L-shaped groove with the posterior limb parallel with 

 the postrostral carina on either branchiostegal region. 



The spines of the carapace, in addition to an acute orbital angle, are a post- 

 orbital, an antennal, a hepatic, and one on the cervical groove behind and above 

 the hepatic. 



Abdominal terga sharply carinated from behind the anterior fourth of the 

 3rd to the end of the 6th. The 6th abdominal somite is not, or hardly, longer than 

 the 5th : the telson is about equal in length to the endopodite of the caudal 

 swimmeret and is " trifurcate." 



Eyes large. Antennular flagella about two-thirds the length of the cara- 

 pace (without rostrum) measured in the mid-dorsal line; though they are 



