— 209 - 



pores very small and relatively few. Multilocular pores quite abundant 

 on the ventral side of the last five abdominal segments. Tubular ducts 

 very small, almost confined to the ventral side, where they are quite 

 abundant near the lateral margins. Legs quite slender, the tarsus 

 slightly less than half as long as the tibia. Antennae (Fig 1 C) slender, 

 8-segmented. Anal ring setae about two thirds as long as the anal 

 lobe setae. Dorsal ostioles with the lips slightly chitinized. 



A specimen that is immature, but is in the last instar, shows the 

 cerarli borne on slight prominences. 



Notes. — This species is one of a group of very closely related 

 forms that includes such species as P. citri, lilacinus and krauhniae. 

 The group is distinguished by the presence of a small but sharply de- 

 fined, chitinized bar on the ventral side of the anal lobes (Fig. 1 D), 

 together with the absence of auxiliary setae and of conspicuously 

 grouped pores in connection with the cerarli. Of these species P. ci- 

 trioides most closely approaches P. liiacinus Ckll. The species known 

 to me may be separated by the following key. 



1. With a single conspicuously elongate, ventral, sub-marginal seta 



near each abdominal cerarius .... citHoides n. sp. 

 Without such setae 2. 



2. Cerarian setae and dorsal body setae somewhat swollen basally, 



with the tips conspicuously flagellate, kreiuhniae (Kuwana). 

 Setae not so 3. 



3. Cerarian setae stout-conical, those on the head nearly as large as 



those of the posterior pairs; lateral margins of the abdomen 

 frequently with setae of the same form as the cerarian setae 

 but smaller (Fig. 1 B); adult female generally rotund . . . 



lilacitnta Ckll. 

 Cerarian setae slender-conical, those on the head somewhat smaller 

 than those of the posterior pairs; lateral margins of the abdo- 

 men never with setae of the same form as the cerarian setae; 

 adult female not rotund citri (Risso). 



Phenacocous cyrenaicus n. sp. 



Fig. 2. 



Material examined. — From undetermined host, El Garib, Cyre- 

 naica. 



Habit. — In life probably with extremely short or no lateral and 

 caudal tassels; probably not secreting an ovisac. 



Morphology. — Form, when flattened on the slide, almost sub- 

 circular. Length 3 mm. With apparently 17 pairs of cerarli but the 

 number somewhat obscured. Each cerarius (Fig. 2 D) with a pair of 



XVI — Botltll. <J> Zoologia a«n. € Agr. 18 



