SPLROBOLUS.— CYCLOTHYROPHORUS. 83 
Hab. Guatemata (Boucard). 
This species was believed by Porat to be very nearly allied to, if not identical with, 
S. mystecus, Sauss., but to differ in having the anal sternal plate rounded or angled, 
not emarginate, and the first tergal plate with its antero-lateral border less excavated. 
13. Spirobolus reptans. 
Spirobolus reptans, Porat, Aun. Soc. Ent. Belg. xxxii. pp. 250, 251 (1888). 
Colour (dry specimen) brownish, posterior border of segments ferruginous or blackish; feet and antenne 
fuscous. 
Head shining, impressed with punctures and wrinkles ; median sulcus interrupted ; labral pores 4 to 5 on each 
side. First tergal plate with the lateral portion acutely triangular, anteriorly sulcate and emarginate. 
Second tergal plate scarcely extending below the level of the first and not excavated beneath. Rest of 
the segments strongly and equally punctate and coriaceous ; transverse sulcus distinct but not deep; the 
lateral sulci extending up to the pores. Anal segment with tergal plate punctate, obtusely angled 
posteriorly ; valves rugose, with margins compressed ; sternal plate posteriorly rounded. 
‘Number of segments 45-46. Length 60 millim.; width 7, of first tergal plate 6. 
Hab. Mexico, Guanajuato (L. Dugés). 
This species seems to differ from all those here referred to Spirobolus in having the 
inferior margin of the second tergal plate produced scarcely below the level of the 
angle of the first, and since its margin is not thickened the segment does not present 
the appearance of being excavated below. 
The following two species, which are unnamed and referred to the genus Lhino- 
cricus, seem to belong without doubt to Spirobolus :— 
Rhinocricus sp., Brélemann, Mém. Soc. Zool. France, xiii. p. 101, t. 7. figg. 66-68 
(1900). 
Hab. Guatemaa (Rodriguez). 
Rhinocricus tsp., Brdlemann, Bull. Soc. Zool. France, xxix. p. 190 (1904). 
Hab. GuateMaLa (Lodriguez). 
CYCLOTHYROPHORUS, gen. nov. 
Nearly allied to Spirobolus, but with the valves of the anal segment strongly convex, their margins not 
compressed or sulcate, but incurved so as to form a re-entering angle or deep triangular groove where 
they meet in the middle line (Tab. VII. fig. 66). Lateral portions of the first tergal plate narrowed, 
triangular, leaving the mandible largely exposed. 
Type, C. salvini. 
In addition to the type-species, I refer tentatively to this genus the three forms 
described as Spirobolus nietanus, heteropygus, and vulvanus, which, so far as I can judge, 
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