It was more startling because both in appearance and manner he suggested a very definite type.

=It was more startling because he suggested a very definite type both in appearance and manner.

(以上为连词because引导原因状语从句）

主句：It was more startling

从句：because he suggested a very definite type both in appearance and manner.

参考译文：更令我吃惊的是他的外表和行为方式使人想到他是某种类型的人。

解析如下：当作“暗示;表明;显示”是个及物动词，后面可以直接跟名词作宾语还可以接宾语从句，不需要在加系动词"be"

suggest  vt.暗示;表明;显示

Earlier reports suggested that a meeting would take place on Sunday. 

早先的报道暗示周日可能会召开会议。

Its hairy body suggests a mammal.  

它毛茸茸的身体表明它是哺乳动物。

His pale face suggests bad health.
他面色苍白，说明他身体不好

Her smile suggests her consent.   
她的微笑意味着同意。

Her expression suggested anger.   
她露出愤怒的表情。

His sun-tanned face suggests good health.   
他那晒黑了的脸说明身体很好。

Her large house suggests wealth.   
她宽敞的住房表明了她的富有。

Harry's bad manner suggests a lack of education.   
哈里的毫无礼貌说明他缺乏教养。