MALLOPHAGA. 555 



tinct jaws. The flattened body is corneous, hard above, and 

 the head is horizontal, with three to five-jointed antennae ; the 

 eyes are small and simple ; the mandibles are small, like a 

 hook, and the maxillary palpi, when present, for they are some- 

 times wanting, are four-jointed, while the labial palpi are two- 

 jointed. The thorax is small and but two-jointed apparently, 

 as the meso- and metathorax are united together. The abdo- 

 men is from nine to ten-jointed, while the short thick limbs 

 have two-jointed tarsi and one or two claws. 



These insects are considered by Burmeister as forming n 

 passage from the Hemiptera into the Orthoptera, as they pos- 

 sess free biting mouth-parts, especially free mandibles, which 

 are not as in the rest of the suborder fused together with the 

 other parts to form a sucking tube. Docoplwrus buteonis Pack, 

 (pi. 9,* fig. 3) lives on the Red Shouldered Hawk ; and D. 

 hamatus Pack. (PI. 9, fig. 7) is found on the Snow Bunting. 



Goniocotes Burnettii Pack. (Fig. 560) infests the domestic 

 fowl. Lipeurus corvi Pack. (PI. 9, fig. 2) is a parasite of the 

 crow ; L. elongatus Pack. (PI. 9, fig. 

 4), and L. gracilis Pack. (PL 9, fig. 

 6) are long and slender forms. In 

 the genus Philopterus of Nitzsch the 

 antennae are filiform, five-jointed, and 

 the labial palpi are wanting. Nir- 

 mus is an allied genus ; both live on 

 birds. N. thoracicus Pack. (PI. 9, 

 fig. 5) lives on the Snow Bunting. 



Tricliodectes canis DeGeer lives on 

 the dog, and has three-jointed an- 

 tennae. The females have two mov- 

 able hooks on the penultimate ring of 

 the abdomen. T. subrostratus is a 



parasite of the cat. T. caprce Pack., lives on the goat. The 

 Saddle-back Gull is inhabited by Colpocephalum lari Pack. (PI. 

 9, fig. 1). Gyropus has no labial palpi. G. porcelli Schrank is 

 a third of an inch long and lives on the Porpoise. Mr. C. 

 Cooke has found G. ovalis on the Guinea pig in this country. 



* EXPLANATION OF PLATE 9. Fig. 1, Colpocephalum lari Pack.; la, antenna; 

 Fig. 2, Lipeurus corvi Pack. ; 2, antenna; Fig. 3, Docophorus buteonis Pack.; 3a, 

 antenna; Fig. 4, Lipeurus elongatus Pack. , 4rt, antennae; Fig. 5, Nirmus thoracicus 

 Pack.; Fig. 6, Lipeurus gracilis Pack.; Fig. 7, Docophorus hamatus Pack. 



